analysis of relationships between water quality parameters
TRANSCRIPT
Winthrop UniversityDigital Commons @ Winthrop
University
Graduate Theses The Graduate School
5-2015
Analysis of Relationships Between Water QualityParameters and Stream Sediment with FecalBacteria in Hidden Creek, Rock Hill, SCKaitlin J. McCullochWinthrop University
Follow this and additional works at: https://digitalcommons.winthrop.edu/graduatetheses
Part of the Biology Commons, and the Terrestrial and Aquatic Ecology Commons
This Thesis is brought to you for free and open access by the The Graduate School at Digital Commons @ Winthrop University. It has been accepted forinclusion in Graduate Theses by an authorized administrator of Digital Commons @ Winthrop University. For more information, please [email protected].
Recommended CitationMcCulloch, Kaitlin J., "Analysis of Relationships Between Water Quality Parameters and Stream Sediment with Fecal Bacteria inHidden Creek, Rock Hill, SC" (2015). Graduate Theses. 14.https://digitalcommons.winthrop.edu/graduatetheses/14
ANALYSIS OF RELATIONSHIPS BETWEEN WATER QUALITY
PARAMETERS AND STREAM SEDIMENT WITH FECAL BACTERIA
IN HIDDEN CREEK, ROCK HILL, SC.
A Thesis
Presented to the Faculty
Of the
College of Arts and Sciences
In Partial Fulfillment
Of the
Requirement for the Degree
Of
Master of Science
In Biology
Winthrop University
April, 2015
By
Kaitlin J. McCulloch
ii
ABSTRACT
Hidden Creek, in Rock Hill, SC is in need of a watershed management
program to decrease fecal coliform counts by 19% because currently, water
samples measured for fecal bacteria exceed the Total Maximum Daily Load
(TMDL). One objective of this study was to locate the area/s along Hidden Creek
with the highest fecal bacteria counts. The other objectives were to determine
whether relationships existed between fecal bacteria and water quality
parameters and whether the stream sediment was serving as a reservoir for fecal
bacteria. Five sampling sites were established and samples were taken every 1-
2 weeks from June – September 2014 (the summer season). At each site,
chemical and physical parameters such as pH, dissolved oxygen, turbidity, and
water temperature, were measured using a Eureka Manta Probe. Undisturbed
and disturbed water samples from each site were analyzed for total fecal coliform
and E. coli. The results showed that disturbed water samples had significantly
higher total fecal coliform and E. coli counts than the samples taken from the
overlying water column. Multiple regression analyses were performed to
examine if DO, water temperature, and turbidity could be used to predict E. coli
or total fecal coliform in Hidden Creek. There were no significant relationships
between any of the factors. The variability in the number of E. coli and total fecal
coliform colonies for each site were large which made it difficult to pinpoint a
specific site of interest. The only sites that had significantly different E. coli
counts were Riverview and Lexington. All other sites were not significantly
iii
different from each other for both E. coli and total fecal coliform. Across all of the
sites combined, E. coli exceeded 235 cfus/ 100 mL and total fecal coliform
exceeded 400 cfus/100 mL greater than 25% of time for both undisturbed and
disturbed samples (the standards set by the Clean Water Act and EPA). This is
a concern because Hidden Creek flows into the Catawba River which provides
recreational uses and drinking water supply for surrounding areas. Overall, this
study concluded that by monitoring bacteria in sediment, as well as the overlying
water column, a more accurate depiction of water quality could be completed.
This would save companies and municipalities time, money, and effort when
creating an effective management program.
iv
ACKNOWLEDGMENTS
I would like to thank Winthrop Research Council for providing the funding to
complete this project. Thanks to Dr. Peter Phillips for being my thesis advisor
and for letting me use his lab and equipment for sampling and analyses. Thanks
to my committee members Dr. Matt Heard and Dr. Bill Rogers for giving me
helpful review comments and suggestions on my project. Special thanks to the
City of Rock Hill Stormwater Division: David Dickson, Renee Burt, and Angela
Jackson for providing me with the information and maps for Hidden Creek and for
sampling with me throughout the summer.
v
TABLE OF CONTENTS
ABSTRACT ii
ACKNOWLEDGEMENTS iv
LIST OF FIGURES vii
LIST OF TABLES viii
INTRODUCTION 1
Clean Water Act 1
Human Impacts on the Stream Environment 3
Effects of Urbanization on Streams 4
The Impact of Urban Streams on Water Quality 6
Fecal Coliform and Urbanization 8
Type and Size of Sediment 10
Taking into Account Resuspension of Sediment and Fecal Bacteria 11
Temperature, Sunlight, and Seasonality 12
Flow of Stream 14
Relationships between Water Quality Parameters
and Fecal Bacteria 15
Site of Interest 19
Objectives 21
Research Questions 22
Hypotheses and Rationale 23
METHODS 25
Watershed Description 25
Description of Sites 25
vi
Sampling Period 28
Field Sampling Methods 28
Laboratory Analysis of Samples 29
Statistical Analysis of Data 31
RESULTS 32
Effect of Site and Disturbance Level on E. coli Colonies 32
Effect of Site and Disturbance Level on Total Fecal Coliform 35
Effect of Water Temperature, DO, and Turbidity on E. coli 37
Effect of Water Temperature, DO, and Turbidity on Total Fecal Coliform 37
Percent Exceedance Calculations 38
Percent Exceedance of E.coli per Site 38 Percent Exceedance of Total Fecal Coliform per Site 40 Percent Exceedance of E.coli and Total Fecal Coliform for Hidden Creek 42
DISCUSSION 43
CONCLUSION 49
LITERATURE CITED 50
vii
LIST OF FIGURES
Figure No. Page
1 The effect of individual factors and their interactions on E. coli survival in fresh water streams 17
2 Map of 16 preliminary sampling points located on 26 Hidden Creek (CW-221) in Rock Hill, SC.
3 Map of the 5 sites along Hidden Creek (CW-221) 27
4 Examples of results obtained from using 3M™ Petrifilm™ E.coli/ Coliform Count Plates 30
5 Mean (± SE) of E. coli colonies between undisturbed and disturbed samples 34
6 Mean (± SE) of total fecal coliform colonies between undisturbed and disturbed samples 36
viii
LIST OF TABLES
Table No. Page
1 Latitudinal and Longitudinal GPS coordinates for the 5 sampling sites on Hidden Creek 27
2 Mean ± SE of E. coli coliform counts for both undisturbed and disturbed samples from all 5 sites 33
3 Mean ± SE of Total Fecal coliform colonies for both undisturbed and disturbed samples from all 5 sites 35
4a Summary statistics for undisturbed E. coli (cfus/100 mL) concentrations 39
4b Summary statistics for disturbed E. coli (cfus/100 mL) concentrations 39
5a Summary statistics for undisturbed total fecal coliform (cfus/100 mL) concentrations 41
5b Summary statistics for disturbed total fecal coliform (cfus/100 mL) concentrations 41
6 Percent Exceedance of fecal bacteria for all of the sites combined 42
7 Mean ± SE of water temperature (ºC), turbidity 45 (NTUs), and DO (mg/L)
1
INTRODUCTION
Rivers and streams are essential to humans because they provide us with
water for drinking, farming, industry, wildlife and recreational purposes, as well as
beauty to our environment. However, as society is becoming more urbanized,
we are causing negative changes to natural water sources. There is plentiful
research demonstrating the negative effects humans are having on watersheds
around the world (Paul & Meyer 2001, Walsh et al. 2005). Due to these negative
impacts, laws and regulations have been established keep water safe and clean
for humans and other animals.
Clean Water Act
The Industrial Revolution was the beginning of a steep cline in population
growth and urbanization in the United States. Around the 1970s, the United
States government began to realize that human population growth and
urbanization were becoming detrimental to the watersheds (EPA 2012). This led
to a series of laws being passed to help clean up the environment. In 1972, the
Clean Water Act (CWA) was passed to attempt to protect and restore waters that
are used by humans (EPA 2012). Since then, many sections have been added
to the CWA to further the goal of keeping water supplies clean. These include
section 319 and section 304 (EPA 2012). Section 319 was established to help
control nonpoint source pollutants, while section 304 pushed states to develop
water quality criteria (WQC) for rivers and streams (EPA 2012). The CWA has
2
been able to regulate point source pollutants by limiting the amount and type of
discharge that can be released into the water, but controlling nonpoint source
pollutants is a more difficult task (EPA 2012).
In addition, section 303(d) of the CWA required each state to provide the EPA
with a list of impaired waters (SCDHEC 2012). If a water source is listed on the
303(d) list, then the water quality of that stream is heavily polluted or degraded
and does not meet the required standards for the CWA (EPA n.d.a.). The EPA
helps states develop water quality criteria by establishing regulations and
guidelines the states are required to follow (Barbour et al. 1999).
As a state begins to implement these regulations and guidelines, it must
develop a Total Maximum Daily Load (TMDL) for the impaired water source (EPA
n.d.a.). This is the maximum amount of a pollutant that a stream or river can
receive daily and still uphold its water quality standards (EPA n.d.a.). The TMDL
is effective because it provides states with a quantified loading capacity for their
bodies of water and helps them to begin the process of restoring the stream by
monitoring and management of the water body (Barbour et al. 1999). TMDL’s
are essentially used for controlling and mitigating stream pollution that is usually
caused by humans (EPA n.d.a.).
In South Carolina, the South Carolina Department of Health and
Environmental Control is responsible for making sure streams meet the
standards set by the EPA and CWA. SCDHEC is accountable for setting up
3
stations along a stream where monitoring by staff can be completed (SCDHEC
1999). Specifically, the standards for fecal coliform state:
Within a 30 day period, 5 consecutive samples cannot exceed a geometric
mean of 200 cfus/100 mL;
During a 30 day period, no more than 10% of the total samples should
exceed 400 cfus/100 mL (SCDHEC 2012).
Samples from a stream station are usually collected over a five year period. If
greater than 10% of the samples over the 5 year period exceed 400 cfus/100 mL,
the stream is considered impaired and is listed on the 303 (d) list (SCDHEC
1999).
Human Impacts on the Stream Environment
Humans, as well as their activities, are the reasons for these water bodies
becoming impaired and degraded. We destroy the natural habitats of these
streams because we use the areas around them for constructing buildings,
farming land, factories, and for creating roads or highways. Specifically, humans
are increasing the urbanization of land which is changing the composition and
health of the environment.
Today, the United States has a population growth rate of 0.77% (Central
Intelligence Agency 2014). As population increases, urbanization also increases
because more and more people need resources, such as a place to live. In the
4
United States, 82.4% of the total population is considered an urban population
and the current rate of urbanization is about 1.14% annual rate of change
(Central Intelligence Agency 2015). To be defined as an ‘urban cluster’ there
must be at least 2,500 people and an ‘urbanized area’ is one with 50,000 people
or more (Census Bureau 2010). In addition to the number of people, the overall
landscape of an urban area is characterized by many man-made structures and
unnatural surfaces such as roads or highways (Wenger et al. 2009). The focus
for my thesis will be on how urbanization affects water quality in streams.
Effects of Urbanization on Streams
Urbanization can affect streams in many ways such as hydrologic
alteration, geomorphologic alteration, and changes in stream flow (Wenger et al.
2009). The overall effects on an urban stream have been coined “urban stream
syndrome” (Walsh et al. 2005).
Hydrologic alteration focuses on how impervious surfaces associated with
urban areas affect streams. These surfaces include parking lots, roads,
sidewalks, and rooftops (Allan 2004). Such impervious surfaces do not allow
water to infiltrate into the ground, which in turn increases runoff from these
surfaces and causes more nonpoint source pollutants to enter into waterways
nearby (Carpenter et al. 1998; Brabec et al. 2002; Wenger et al. 2009). Nonpoint
source pollutants are a difficult problem to control because they do not come
from a single source, such as a drainage pipe (Carpenter et al. 1998). Nonpoint
source pollutants can encompass a variety of materials such as sediments, fecal
5
matter, fertilizers, heavy metals, and petroleum-derived hydrocarbons (Carpenter
et al. 1998; Marti et al. 2004; SCDHEC 2012).
In addition to hydrologic alteration, geomorphologic alterations affect
urban streams. Stream modifications include widening, straightening,
deepening, piping, or filling the stream channel (Booth et al. 2002; Allan 2004;
Walsh et al. 2005). Changing the stream shape reduces bank stability which in
turn can lead to erosion of soil and trees into the stream and, in some cases, can
initiate big landslides (Booth 1991). Bank erosion causes increased
sedimentation in the streams, which, like nonpoint source pollutants, can lead to
changes in available habitats for aquatic organisms (Booth 1991).
Geomorphologic alterations also include riparian zone clearing which increases
sunlight exposure of the stream and decreases the stability of stream banks
(Allan 2004).
Urban streams are also prone to increased flow which can be attributed to
many changes in the geomorphology of the stream (Walsh et al. 2005). For
example, piping or changing the channel shape causes increased stream flow
(Walsh et al. 2005). Urban streams tend be labeled as ‘flashy streams’ because
they often have large flow events during storms followed by slow flow events
(Walsh et al. 2005). Because of these large flow events, many urban streams
flood during storms (Booth 1991). In addition, this increased flow leads to
smaller sediments or rocks being carried downstream, while coarser, bigger
rocks remain (Schoonover et al. 2005). Changes in flow to an urban stream lead
6
to changes in the diversity and abundance of organisms that can live in this sort
of habitat (Booth 1991).
The Impact of Urban Streams on Water Quality
Although the above factors are the main ways that urbanization affects the
overall structure of a stream, it is important to look in more detail at the actual
water quality and the communities of aquatic organisms in the stream to assess
the true human impact. The effects of urbanization on water quality and aquatic
organisms in a stream have been extensively studied for many years. Each
organism or water quality parameter is affected differently depending on the state
of the impaired stream and the major pollutant in the stream. Important water
quality parameters include conductivity, total suspended solids, temperature, pH,
dissolved oxygen, and nutrient concentration (SCDHEC 2012).
“Urban stream syndrome” leads to increased levels of total suspended
solids (TSS), as well as increased temperatures in warmer months (Porcella &
Sorensen 1980). Total suspended solids (TSS) is measured by examining the
number of particles in water that will not pass through a filter with a pore size
between 0.45 -1.5 µm (Barbour et al. 1999). For example, particles such as sand,
silt, and algae could affect TSS levels (Barbour et al. 1999). Another way to
measure TSS is by testing turbidity levels. Turbidity is a measure of water clarity
that determines the degree to which light can travel through the water column
(Barbour et al. 1999).
7
When considering temperature, studies have found a five to eight degree
Celsius increase in the summer and a one and a half to three degree Celsius
decrease in the winter in urban streams when compared to forested streams
(Pluhowski 1970; Leblanc et al. 1997). A review by Allan (2004), argued that
reduction or clearing of riparian barriers in urban areas is a main contributor to
increasing temperatures in water, as well as to runoff and point source pollutants.
Increase in temperature has also been shown to lead to decreased dissolved
oxygen (DO) in the water because warmer water holds less oxygen than cooler
water (Allan 2004). Furthermore, these decreases in DO are negatively
correlated with biological oxygen demand (BOD) levels (Barbour et al. 1999).
The EPA defines BOD as the amount of oxygen that is consumed by
microorganisms for decomposition of organic matter (Barbour et al. 1999).
Higher BOD levels lead to a rapid depletion of oxygen in the stream which can
cause aquatic life, such as fish or crayfish, to become stressed and suffocate
(EPA n.d.b). Sources of high levels of BOD include leaves, dead plants and
animals, and animal manure (EPA n.d.b.).
As mentioned before, urban streams are greatly affected by nonpoint
source pollutants in runoff, especially during storms. This leads to changes in
the levels of nutrients, metals, and ion concentrations in urban streams (Porcella
& Sorensen 1980; Ometo et al. 2000; Winter & Duthie 2000). It is hard to
pinpoint where these ions and nutrients are originating because they are mostly
found in storm water runoff (Carpenter et al. 1998). It also has been found that
8
these nutrients and ions can get into the stream via ground water (Booth 1991).
Certain nutrients, especially nitrates and phosphates, when increased, can lead
to excessive algal growth or blooms in streams (Carpenter et al. 1998). When
algae die, their decomposition consumes valuable oxygen which contributes to a
decline of oxygen available for aquatic organisms (Carpenter et al. 1998).
Fecal Coliform and Urbanization
“Fecal coliform” refers to a pathogen community in streams that is
composed of bacterial colonies that are usually present in the fecal matter of
animals (EPA n.d.c). The EPA (2012) states that fecal coliform is a good
indicator of potential for human illness from recreational water. Escherichia coli is
a species of bacteria found in fecal matter of humans and other endotherms
which makes it a good indicator of potential human illnesses from the water (EPA
2012). Obtaining data on fecal coliform and E. coli concentrations in streams is a
key component to understanding the water quality of an area. Both fecal coliform
counts and E. coli counts are acceptable for measuring fecal contamination in
water (EPA 2012). The specific method depends on the state’s preference (EPA
2012).
Fecal matter can enter the stream directly, via organisms defecating in the
water, or indirectly, via runoff from the surface (Paul & Meyer 2001; Walsh et al.
2005). Acceptable levels for total fecal coliform in ambient water conditions are
400 colony forming units (cfu) per 100 mL of water and 235 cfus/ 100 mL for E.
9
coli (EPA 2012). Studies have shown that urban streams tend to have fecal
coliform counts that are higher than most rural and forested streams (Young &
Thackston 1999; Schoonover 2005). In addition, research has shown that fecal
bacteria levels are related to density of housing, population, development,
impervious surfaces, and domestic animal density (Young & Thackston 1999;
Mallin et al. 2000). Mallin et al. (2000) observed that the most significant factor
influencing fecal bacteria loads was the percentage of impervious surfaces
around the stream site. Therefore, the more impervious surfaces there are, the
higher the fecal counts (Mallin et al. 2000).
The survival of fecal bacteria in streams depends on the stream properties
and water quality. One of the biggest factors that can lead to extended survival
of E.coli in streams is the characteristics of the stream bed. Stream beds can
become a reservoir for bacteria depending on the type and size of substrate
material (Burton et al. 1987; Sherer et al. 1992; Kim et al. 2010). Many studies
have found that bacteria levels are associated with sediment in streams and the
sediment can lead to increased survival of E.coli (Matson et al. 1978;
Stephenson & Rychert 1982; Gannon et al. 1983; Sherer et al. 1992; Jamieson
et al. 2005; Garzio-Hadzick et al. 2010). This association between sediment and
E.coli creates a very complicated issue when trying to assess water quality of an
area (Jamieson et al. 2005). Methods for collecting and examining water
samples for E.coli do not account for the E. coli stored in sediment because the
10
associations between sediments and E. coli are not fully understood or
characterized (Howell et al. 1996; Jamieson et al. 2005).
Bacteria typically are attracted to and persist in certain types and sizes of
sediments. Both bacteria and most sediment in the aquatic environment are
negatively charged and Jamieson et al. (2005) hypothesized that bacteria are
drawn to the solid surfaces of the sediment by London-van der Waals forces
initially. Once the bacteria become associated with the sediment by van der
Waals forces, the bond between the bacteria and sediment can become stronger
and more permanent over time (Jamieson et al. 2005).
The depth within sediment that E. coli can survive is another important
variable. Most E. coli prefer the top layer of the sediment, specifically the upper
centimeter (Garzio-Hadzick et al. 2010; Kim et al. 2010). A study by Garzio-
Hadzick et al. (2010) observed that the concentration of E. coli decreased by
about 1 order of magnitude per 2 centimeters of sampling depth probably due to
the availability and accessibility to nutrients in the top most layers (Garzio-
Hadzick et al. 2010).
Type and Size of Sediment
Often, E. coli is found in sediments that are fine (less than 60
micrometers) and have certain organic contents (Gannon et al. 1983; Garzio-
Hadzick et al. 2010). For example, E.coli was observed to have a lower mortality
rate in clay-sized sediments (about 2 micrometers or less in diameter) than in
11
coarser sediments (Howell et al. 1996). Burton et al. (1987), monitored fecal
bacteria over 14 days in different sediment types and observed that the survival
of E. coli was greatest in sediments with at least 25% clay (Burton et al. 1987).
Most researchers agree that the smaller the particle size, the greater the
survival of fecal coliform (Gannon et al. 1983; Howell et al. 1996; Garzio-Hadzick
et al. 2010). However, one study contradicts this conclusion. Peter Cinotto
(2005) recognized that E. coli in the West Branch Brandywine Creek in
Pennsylvania survived longer in sediment with larger particle sizes ranging from
125-150 micrometers. He hypothesized that this could be due to the increased
porosity, permeability, and nutrient availability created by the larger particles
sizes (Cinotto 2005). These contradictory studies can be attributed to the fact
that not everything about the association between fecal bacteria and sediment
has been fully understood.
The length of E. coli survival is also dependent on sediment. For instance,
a study by Sherer et al. (1992) discovered that when incubated with 500 g of fine
sediment and 100 g of water, E. coli had a half-life of about 11 to 30 days which
is higher than the survival rate for E. coli in the water column.
Taking into Account Resuspension of Sediments and Fecal Bacteria
Disturbances within the stream bed can cause E. coli in the sediment to
become resuspended in the water column. Events such as precipitation, floods,
and disturbances by animals and humans are the main causes of sediment
12
resuspension (Stephenson & Rychert 1982; Vidon et al. 2008). Resuspension
permits the transportation of E. coli to new areas of the stream (Jamieson et al.
2005). During precipitation events, Jamieson et al. (2003) discovered that the
downstream sites in their study stream had higher levels of total suspended
solids and bacteria concentrations demonstrating that E. coli can, and often do,
travel with sediment to downstream sites.
The effect of rainfall events and floods on E. coli concentrations has also
been studied. Craig et al. (2004) observed that rainfall events caused an
increase in fecal coliform concentration in coastal water. In addition, they
observed that it took 7 days after the storm event for water quality guidelines to
be met in the stream sediment, compared to only 5 days for the overlying water
(Craig et al. 2004). Muirhead et al. (2004) used artificial flooding to observe how
the stream will be affected and discovered that E. coli concentrations increased
by two orders of magnitude during and after the flooding.
It is very difficult to predict and model the resuspension of the bacteria
(Jamieson et al. 2005; Kim et al. 2010). Questions that are difficult to answer for
streams include the concentration of bacteria that will be resuspended and how
far will the bacteria travel (Pandey et al. 2012).
Temperature, Sunlight, and Seasonality
Other abiotic factors that can determine the survival of E. coli over time
include temperature, sunlight, and the season. Water temperature can play a
13
role in the mortality rates of E. coli. Most studies have found an inverse
relationship between temperature and survival (McFeters & Stuart 1972; Faust
1982; Howell et al. 1996; Craig et al. 2004). Flint (1987) examined E. coli
survival at four different temperatures and concluded that survival decreased as
the temperature increased and the slowest bacterial decay rate of E. coli was at
4°C (Flint 1987). In fact, Garzio-Hadzick et al. (2010) observed that 4°C had the
highest persistence of E. coli. At 24°C, they observed the highest mortality rate
of E. coli (no E. coli survived) after one week (Garzio-Hadzick et al. 2010).
E. coli in coastal sediment was found to persist for more than 28 days when
incubated at 10° C (Craig et al. 2004). In sum, lower temperature increases
survival of E.coli while higher temperature decreases survival.
There is also a seasonal component that affects fecal coliform counts.
Fecal coliform have been observed to be higher in the months of April through
September compared to the other months (Clark & Norris 2000; Young &
Thackston 1999). Summer months are associated with more intense
thunderstorms than the winter, which leads to greater accumulation of fecal
bacteria into stream runoff (SCDHEC 1999). The winter is characterized by slow
rainfall events that usually do not cause huge spikes in fecal bacteria in a stream
(SCDHEC 1999). Therefore, when examining water samples it is important to
recognize the relationship between seasonality and temperature. Increased
water temperature leads to decreased survival of E. coli but, overall, there is
more fecal matter in streams during summer and spring.
14
Besides temperature and other seasonal effects, the amount of sunlight
that directly or indirectly impinges on the stream can affect E. coli survival
(Davies & Evison 1991; Sinton et al. 2002). The greater the intensity and time
that fecal bacteria are exposed to sunlight, the faster the decay rate (Davies &
Evison 1991; Sinton et al. 2002). The studies by Davies and Evison(1991) and
Sinton et al. (2002) were not able to confirm what role UV rays played in the
decay rate of fecal bacteria; however, they did conclude that more direct sunlight
on a stream leads to increased water temperature in that area. As noted above,
increased water temperature decreases the survival of E. coli.
Flow of Stream
The intensity of flow in a stream can affect the survival and transport of E.
coli (Matson et al. 1978; Jamieson et al. 2003; Kim et al. 2010). As mentioned
previously, disturbance events that cause changes in stream flow can lead to
resuspension of E. coli from sediments (Craig et al. 2004; Muirhead et al. 2004).
When mean velocity of streams is higher, fecal coliform is also higher at that site
(Matson et al. 1978; Vidon et al. 2008). The faster velocity of water causes an
increase in the amount of sediment and associated E. coli being resuspended in
the water column (Craig et al. 2004; Muirhead et al. 2004). However, some
studies contradict this observation. Kim et al. (2010) found that when the
velocity is low, E. coli concentrations are at their highest because the E. coli
accumulates in one area and are only slowly transported downstream.
Therefore, if samples were taken in an area of slow flow, E. coli numbers could
15
be very high because many colonies have accumulated in that area. These
contradictory data demonstrate that E. coli varies in the way that it responds to
conditions and the environment (Wickham et al. 2006). By not separating base
flow and high flow events in models, important patterns of the system might not
be revealed (Wickham et al. 2006).
Relationships between Water Quality Parameters and Fecal Bacteria
Variables that affect the persistence of E. coli are not independent of each
other (Figure 1). More than one abiotic or biotic condition may need to be met in
order for E. coli to persist (McFeters & Stuart 1972). Chemical and physical
parameters such as pH, nutrient concentration, dissolved oxygen, turbidity, and
conductivity must all be within a certain range to allow for bacteria survival
(Wickham et al. 2006). For example, McFeters and Stuart (1972) observed that
pH levels between 5.5 and 7.5 are optimal for survival of bacteria and anything
below or above that range caused a rapid decline in E. coli levels.
In addition, turbidity interacts with other factors. As turbidity increases, the
particles are able to absorb more heat which leads to increased water
temperature (Paaijmans et al. 2008). Increased levels of suspended solids also
reduce the amount of sunlight that can penetrate the water (Craig et al. 2004).
During storm events, turbidity was found to be 8 - 10 times greater than in dry
weather samples because storm events lead to increased sediment runoff and
16
increased bank erosion, as well as resuspension of stream bottom sediment
(Lawrence 2008).
Dissolved oxygen may also affect fecal coliform in streams but studies are
contradictory. Researchers found no correlation between fecal coliform and
dissolved oxygen (Mallin et al. 2000). On the other hand, Nevers & Whitman
(2005) and David & Haggard (2011) found a significant negative correlation
between fecal coliform and dissolved oxygen. Based on these studies, it is
apparent that there is not enough data to confirm whether significant correlations
exist between fecal coliform and dissolved oxygen. More research is needed on
this subject to help understand the relationships in streams.
17
E. coli
Survival
Sediment
type & sizeResuspension
of sedimentsFlow
Water
Temperature
Physical and
Chemical
Parameters
Air temp.,
sunlight,
seasonality
Figure 1. The effect of individual factors and their interactions on E. coli survival in fresh water streams. The dark blue arrows indicate that each factor has an effect on E. coli survival. The light blue arrows indicate the interactions that are occurring between the factors.
18
Understanding interactions and relationships between fecal bacteria and
the variables associated with a stream bring to light the difficulty that comes
when creating a model for predicting E. coli levels. This is strongly influenced by
the uncertainty involved in predicting resuspension of sediments (Pandey et al.
2012). Even researchers who have attempted to model resuspension admit that
resuspension mechanisms and how they affect E. coli are not fully understood
(Cho et al. 2010; Kim et al. 2010; Pandey et al. 2012). Complex processes
influence the water quality, the sediment type, the flow, and the resuspension of
sediments within a stream (Wilkinson et al. 1995).
Research on this area needs to become a more collaborative process.
Ideas and knowledge that are already present need to be understood in the
context of other factors. A stream system is not created by independent
variables; it is a group of interacting and interrelated influences that create
conditions and an environment affecting survival of E. coli. Studying the
relationships between fecal bacteria and several water quality parameters
simultaneously in individual streams, can help bring light to the bigger picture. It
is important to examine individual streams because every stream is exposed to
different conditions. Those different conditions could help reveal factors and
interactions that can further the research in this field.
19
Site of Interest
This project focuses on Hidden Creek (station # CW-221) in Rock Hill,
South Carolina in the Catawba River Basin. Hidden Creek is currently listed on
the 303 (d) list because during the 5 year sampling period (1994 –1998) by
SCDHEC, 43% of the samples exceeded 400 cfus/100 mL. In 1999, a TMDL for
fecal coliform was developed to determine the maximum amount of fecal coliform
that Hidden Creek can receive and still meet the water quality standards of the
state (SCDHEC 2012). Due to high fecal coliform numbers, recreational activities
are ‘not supported’ by SCDHEC in Hidden Creek (SCDHEC 2012). The term ‘not
supported’ implies that greater than 25% of water samples from this creek
contain more than the 400 cfus/100 mL standard for swimmable water set by the
Clean Water Act (SCDHEC 2012).
The watershed that Hidden Creek is located in has moderate to high
population growth potential (SCDHEC 2012). All properties along the stream are
considered to be in an urban area (SCDHEC 2012). Because there are no point
source pollutants that lead into this stream, SCDHEC has hypothesized that the
high fecal levels are from nonpoint sources (SCDHEC 2012). SCDHEC (2012)
hypothesized that the fecal bacteria could be originating from storm water runoff,
sewage leakage, overflow of sanitary sewers, failing septic tanks, and domestic
or non-domestic animals’ feces.
In order for Hidden Creek to meet standards, a 19% reduction in fecal
20
coliform loading is necessary (SCDHEC 2012). Due to the need for research on
this stream, I was asked by the City of Rock Hill to study this stream and help
them monitor and locate the areas of concern. The city will use my results to
develop a plan to mitigate and control the level of fecal coliform in the stream.
21
Objectives
The overall goal of my project was to perform an in-depth water quality
analysis on Hidden Creek with a specific focus on the number of fecal coliform
and E. coli colonies. My research will provide information to the city of Rock Hill
that can be used to benefit Hidden Creek’s overall stream health and eventually,
remove it from the EPA’s 303(d) impaired streams list. My study will also be
valuable to the field of freshwater biology because it will increase the knowledge
of how fecal bacteria persist in stream sediment and relate to abiotic factors in an
urban stream. This is important because these freshwater streams and rivers
are where much of the area’s drinking water is obtained.
The specific objectives were to:
• Collect chemical and physical water quality parameters for each site on
Hidden Creek;
-ex. temperature, dissolved oxygen, nutrients, and turbidity
• To assess whether the sediment serves as a reservoir for fecal bacteria;
• To assess what relationships exist between fecal bacteria and water
quality parameters in the stream;
• To locate the source or area that has the highest fecal coliform counts.
22
Research Questions
1. Is there a difference in E. coli numbers between the overlying water column
and the disturbed sediment?
2. Is there a difference in total coliform numbers between the overlying water
column and the disturbed sediment?
3. Is there a relationship between E. coli and DO, turbidity, and/or water
temperature?
a. If so, can we use DO, turbidity, and/or water temperature to predict
the presence of E. coli in a stream?
4. Is there a relationship between total coliform and DO, turbidity, and/or water
temperature?
a. If so, can we use DO, turbidity, and/or water temperature to predict
the presence of total coliform in a stream?
23
Hypotheses and Rationale
I hypothesized that both E. coli and total coliform colonies would be
greater in the water samples that were disturbed. This is because the
disturbance of the bottom sediment initiates a resuspension event of fecal
bacteria from the sediment and into the water column.
Second, I hypothesized that there would be a negative correlation
between DO and fecal coliform which would be consistent with the findings of
Nevers & Whitman (2005) and David & Haggard (2011). Low dissolved oxygen
is often found in streams with slow stream flow. Therefore, I hypothesized the
areas with low dissolved oxygen would have higher fecal coliform counts
because low flow areas allow for coliform to persist longer (Kim et al. 2010).
As the temperature of the water increases, I hypothesized that there would
be lower fecal coliform counts (McFeters & Stuart 1972; Faust 1982; Howell et al.
1996; Craig et al. 2004). Although fecal bacteria are more abundant in the
summer (due to increased rainfall and runoff), they survive longer and seem to
persist more where the water temperature is cooler.
Finally, I hypothesized that turbidity and fecal coliform would be positively
correlated. High turbidity levels can be attributed to increased runoff of sediment
into the stream which could cause the fecal coliform associated with the
sediment to enter the stream (SDHEC 2012).
24
The major goal of my project is to help the city of Rock Hill with one of its
most impaired streams. Because Hidden Creek empties into the Catawba River,
understanding its overall water quality and developing mitigation techniques for
pollutants in the stream can contribute to the health of the Catawba River. The
Catawba River supports many recreational activities such as fishing, kayaking,
and boating and is an important water supply for downstream communities.
Therefore, it is essential to maintain the water quality of the river so that
recreational purposes can continue to be supported.
25
METHODS
Watershed Description
The stream of interest, Hidden Creek, is located in the Catawba River
Basin Watershed. This watershed consists mainly of the Catawba River and its
tributaries and it is located in the Piedmont region of South Carolina within York,
Chester, and Lancaster counties (SCDHEC 2012). The watershed covers about
61.3% forested land, 17.8% urban land, 15.3% agricultural land, and the
remainder 6% falling under water, swamp, or barren land (SCDHEC 2012).
Hidden Creek covers about 182 hectares of land and all of the land is considered
to be in an urban area (SCDHEC 1999).
Descriptions of Sites
The City of Rock Hill chose 16 sites that could be potential causes for high
fecal bacteria in Hidden Creek. All sites were chosen because they were directly
downstream from a sewer line (Figure 2). Of the 16 sites, only 6 were part of the
open stream channel, while the remaining 10 could only be accessed by
manholes. One of the 6 open stream sites was very steep and inaccessible for
sampling. Therefore, only 5 sites were sampled (Figure 3). The site names
(listed from downstream to upstream) were: Paces River, Lexington, Riverview,
Stoney Point 1, and Stoney Point 2 (Table 1).
26
Figure 2. Map of 16 preliminary sampling points located on Hidden Creek (CW-221) in Rock Hill, SC.
27
Figure 3. Map of the 5 sites along Hidden Creek (CW-221) chosen to be examined for fecal bacteria and other chemical parameters (red hexagons). Green lines indicate the boundary of the Hidden Creek Watershed.
Table 1. Latitudinal and longitudinal GPS coordinates for the 5 sampling sites on
Hidden Creek in Rock Hill, SC listed from downstream (closest to the Catawba
River) to upstream.
Site Name Longitude Latitude
Paces River 80°59'28.939"W 34°59'9.564"N
Lexington 80°59'32.577"W 34°58'52.792"N
Riverview 80°59'40.942"W 34°58'44.132"N
Stoney 1 80°59'54.833"W 34°58'29.141"N
Stoney 2 80°59'54.483"W 34°58'30.242"N
28
Sampling Period
Sites were sampled during the summer season of 2014 which began June
21 and ended September 21. The sites were all sampled on the same day every
1-2 weeks depending on the weather for a total of 10 sampling dates. Sampling
could only be completed if less than 0.1 in (2.54 mm) of rain occurred within 24
hours of the proposed sampling date. This is recognized as ‘dry conditions’ for
water sampling methods (Hauer & Lamberti 1996). ‘Dry’ weather sampling
creates a baseline of water quality data that can be used to compare against
future conditions. It is also used to target illegal discharge from business or
isolate sewage/septic system leakages. For example, it can be used to target
potential businesses that are illegally discharging liquid into a sewer system.
Field Sampling Methods
While at each site, the water was analyzed for temperature, dissolved
oxygen, turbidity, and pH using a Eureka Manta Probe. Water temperature was
measured in degrees Celsius, dissolved oxygen was measured in mg/L, and
turbidity was measured in NTUs (Nephelometric Turbidity Units). Simultaneously,
grab samples were collected using methods proposed by the EPA and SDHEC
(Barbour et al. 1999; SDHEC 2012). Two types of grab samples were taken from
each site; one was taken from undisturbed overlying water, while the other was
taken after disturbing the bottom sediment of the stream for 10-15 seconds.
29
The first grab sample was obtained by standing on the edge of the bank
and filling a 50 mL plastic, sterile container with the undisturbed overlying stream
water. The second grab samples were obtained by using a course brush to
scrape the bottom sediment and rocks, causing resuspension of materials into
the water column. Both grab samples were then sealed and placed on ice until
they were transported to the lab.
Laboratory Analysis of Samples
At the lab, both the undisturbed and disturbed samples were analyzed for
fecal bacteria and nutrients within 8 hours of collection (Hach 1997). To
determine total fecal coliform and E. coli counts, 3M™ Petrifilm™ E.coli/
Coliform Count Plates were used (3M™ Petrifilm™ EC Plates). From each
sample, 1 mL of water was placed on the center of the film and the gel was
allowed to solidify. The samples were then placed in an incubator for 24 hours
at 44.5 ± 0.2°C (APHA et al. 1999). The samples were analyzed according to the
Interpretation Guide provided by 3M™ Petrifilm™ (examples in Figure 4). Blue
colonies with gas bubbles were recognized as E. coli. Total fecal coliform was
calculated by adding total red colonies with gas bubbles and total E. coli
colonies. Results were recorded using cfus / 100mL units.
30
Figure 4. Examples of results obtained from using 3M™ Petrifilm™ E.coli/ Coliform Count Plates to determine E. coli and total fecal coliform counts. A. The results for A would be 100 cfus/100 mL E. coli and 200 cfus/100 mL total coliform. B. The results for B would be 400 cfus/100 mL E. coli and 500 cfus/100 mL total fecal coliform.
Additionally, undisturbed and disturbed water samples were analyzed for
total nitrogen, total phosphorus, and organic phosphate concentrations using a
Hach DR 4000 spectrophotometer. The Persulfate Digestion method was used to
determine total nitrogen in the samples (Hach 10071). The Molybdovanadate
method was used to measure the concentration of phosphate (PO43-) in the water
sample (Hach 8114). The Hach method used for measuring Total Phosphorus
was the PhosVer3 with Acid Persulfate Digestion Method (Hach 8190).
31
Statistical Analysis of Data
The data collected from Hidden Creek were first analyzed using a 2-way
ANOVA. The first analysis examined whether there was a difference between E.
coli counts between sites and between undisturbed and disturbed samples. The
same analysis was then completed again using total fecal coliform in place of E.
coli.
The data were then analyzed by using a multiple regression to examine
whether there were relationships between number of E. coli colonies and DO,
water temperature, and turbidity. In the multiple regression, E. coli was the
dependent variable and DO, water temperature, and turbidity were the
independent variables. The same analysis was repeated except using total fecal
coliform as the dependent variable.
Due to a sewage pipe break, the data obtained on September 19, 2014 for
Paces River were excluded from all of the analyses.
32
RESULTS
Effect of Site and Disturbance Level on E. coli Colonies
The first analysis examined whether the specific site and disturbance level
(undisturbed or disturbed sample) affected the number of E. coli colonies in a
sample. A 2-way ANOVA was performed using the square root of E. coli colony
counts. Data were transformed so that homogeneity of variances could be
assumed. Assumptions of normality could not be met for the data, but ANOVAs
can deal with non-normal data. The results showed that the model was
significant (F = 2.826; P = 0.006; n = 98). There was a significant effect of site
on the number of E. coli colonies in a sample (F = 3.067; P = 0.02). Using the
Gabriel Post Hoc test and Pairwise comparisons, a significant difference was
found between Riverview and Stoney Point 2 (Table 2). The Gabriel Post Hoc
test was used because samples sizes were slightly different between the sites.
All other sites were not significantly different from each other (Table 2).
33
Table 2. Mean ± SE of E. coli colonies (cfus/ 100 mL) for both undisturbed and
disturbed samples for all 5 sites located on Hidden Creek taken from June 30 –
September 18, 2015 (total n = 98; all sites had n = 10 for undisturbed and
disturbed samples, except Paces River which had n = 9). Superscript letters
indicate results from the Gabriel Post Hoc test. Sites with the same letters are
not significantly different from each other; sites with different letters are
significantly different from each other.
E.coli (cfus/ 100 mL)
Undisturbed Disturbed
Paces River
511.11 ± 172.76 C 533.33 ± 113.04 C
Lexington 450.00 ± 131.87 C 800.00 ± 278.89 C
Riverview 400.00 ± 100.00 A, C
510.00 ± 65.74 A, C
Stoney #1 510.00 ± 91.23 C
830.00 ± 176.42 C
Stoney # 2 640.00 ± 131.83 B, C
1570.00 ± 534.38 B, C
34
The model also showed that there was a significant effect of disturbance
level on the number of E. coli colonies in a sample (F = 9.262; P = 0.003;
Figure 5). Samples that were taken after stream sediment was disturbed
(855.10 ± 136.90 cfus/ 100 mL; mean ± SE) were significantly higher in E. coli
colony counts than undisturbed samples (502.04 ± 55.52 cfus/ 100 mL). There
was no significant interaction between site and disturbance levels on the model
(F = 0.896; P = 0.470).
Figure 5. Mean (± SE) E. coli colonies (cfus/ 100 mL) between undisturbed and
disturbed samples across all 5 sites located on Hidden Creek taken from June 30
– September 18, 2015 (n = 49 for undisturbed and disturbed samples).
0
200
400
600
800
1000
1200
Undisturbed Disturbed
E.
co
li (
cfu
/100m
L)
Disturbance Level
35
Effect of Site and Disturbance Level on Total Fecal Coliform
The second analysis examined whether the specific site and disturbance
level (undisturbed or disturbed sample) affected total fecal coliform colonies in a
sample. A square root transformation for total fecal coliform was performed to
normalize the data and allow for equal variances. The results of the 2-way
ANOVA showed that the model was not significant (F = 1.942; P = 0.056; n = 98).
There was no significant effect of site on the number total fecal coliform colonies
in a sample (F = 1.759; P = 0.144; Table 3).
Table 3. Mean ± SE of Total Fecal coliform colonies (cfus/ 100 mL) for both
undisturbed and disturbed samples for all 5 sites located on Hidden Creek taken
from June 30 – September 18, 2015 (total n = 98; all sites had n = 10 for
undisturbed and disturbed samples, except Paces River which had n = 9).
Total Fecal Coliform (cfus/ 100 mL)
Undisturbed Disturbed
Paces River
788.89 ± 319.05 833.33 ± 184.84
Lexington 820.00 ± 232.76 1410.00 ± 409.73
Riverview 820.00 ± 189.62 1010.00 ± 179.78
Stoney #1 850.00 ± 141.62 1250.00 ± 236.76
Stoney # 2 990.00 ± 192.325 1970.00 ± 529.58
36
There was significant effect of disturbance level on total fecal coliform in a
sample (F = 7.842; P = 0.006; Figure 6). Samples that were taken after stream
sediment was disturbed (1304.08 ± 157.30 cfus/ 100 mL; mean ± SE) had
significantly higher total fecal coliform colonies than undisturbed samples (855.10
± 94.09 cfus/ 100 mL). There was no significant interaction between site and
disturbance levels on the model (F = 0.589; P = 0.671).
Figure 6. Mean (± SE) total fecal coliform colonies (cfus/ 100 mL)between
undisturbed and disturbed samples across all 5 sites located on Hidden Creek
taken from June 30 – September 18, 2015 (n = 49 for undisturbed and disturbed
samples).
0
200
400
600
800
1000
1200
1400
1600
Undisturbed Disturbed
To
tal F
ecal
Co
lifo
rm (
cfu
/100m
L)
Disturbance Level
37
Effect of Water Temperature, DO, and Turbidity on E. coli
A multiple regression analysis was performed using the square root values
of E. coli colonies as the outcome variable and water temperature, DO, and
turbidity as the predictor variables. The results of the multiple regression analysis
indicated that there was no significant model when using water temperature, DO,
and turbidity to predict E. coli in Hidden Creek (F = .400; P = 0.754; n = 49). The
R2 value is 0.026 which means only 2.6% of the variation in E. coli colonies is
explained by this model. There were no significant correlations between the
number of E. coli colonies and the three independent variables.
Effect of Water Temperature, DO, and Turbidity on Total Fecal Coliform
A multiple regression analysis was performed using the square root values
of total fecal coliform colonies as the outcome variable and water temperature,
DO, and turbidity as the predictor variables. The results of the multiple regression
analysis indicated that there was no significant model when using water
temperature, DO, and turbidity to predict total fecal coliform colonies in Hidden
Creek (F = 1.493; P = 0.229; n = 49). The R2 value is 0.091 which means only
9.1% of the variation in total fecal coliform colonies is explained by this model.
There were no significant correlations between the total fecal coliform and the
three independent variables.
38
Percent Exceedance Calculations
Percent Exceedance of E.coli per Site
Undisturbed samples measured for E. coli illustrated that all individual
sites had greater than 25% exceedance of 235 cfus/100mL, which is above the
standard set forth by the EPA (Table 4A; SCDHEC 2012). The lowest percent
exceedance was 60% at Riverview, while the highest percent exceedance was
80% at Stoney 1 and Stoney 2. Throughout the sampling period, the minimum
number of E. coli colonies at any individual site was 0 cfus/100 mL which was
observed at Lexington, while the maximum was 1800 cfus/100 mL which was at
Paces River. The minimum mean ± SE for undisturbed E. coli samples was
400.00 ± 100.00 cfus/100mL at Riverview and the maximum mean ± SE was
640.00 ± 131.83 cfus/100mL at Stoney 2.
Disturbed samples measured for E. coli also showed that all individual
sites had greater than 25% exceedance of 235 cfus/100mL (Table 4B). The
lowest percent exceedance was 66.7% at Paces River, while the highest percent
exceedance was 100% at Stoney 2 and Riverview. Throughout the sampling
period, the minimum number of disturbed E. coli colonies was 100 cfus/100mL at
Paces River, while the maximum was 6200 cfus/100mL at Stoney 2. The
minimum mean ± SE observed was 510.00 ± 65.74 cfus/100mL at Riverview and
the maximum mean ± SE observed was 1570.00 ± 534.38 cfus/100mL at Stoney
2.
39
Table 4. Summary statistics for E. coli (cfus/ 100 mL) undisturbed and disturbed
sample concentrations for each sampling site on Hidden Creek where n = 10 for
all sites, except Paces River (case on September 19, 2014 excluded from
analysis). % Exceedance is the percentage of samples for each site that exceed
235 cfus/ 100 mL (standard set by EPA).
A. Undisturbed E.coli
Site Name Mean ± SE Min Max % Exceedance
Paces River 511.11 ± 172.76 100
1800 77.8%
Lexington 450.00 ± 131.87 0 1400 70%
Riverview 400.00 ± 100.00 100 1000 60%
Stoney 1 510.00 ± 91.23 100 900 80%
Stoney 2 640.00 ± 131.83 100 1200 80%
B. Disturbed E. coli
Site Name Mean ± SE Min Max % Exceedance
Paces River 533.33 ± 113.04 100 1100 66.7%
Lexington 800.00 ± 278.89 200 3200 90%
Riverview 510.00 ± 65.74 300 900 100%
Stoney 1 830.00 ± 176.42 200 2100 90%
Stoney 2 1570.00 ± 534.38 400 6200 100%
40
Percent Exceedance of Total Fecal Coliform per Site
All individual sites had greater than 25% exceedance of 400 cfus/100mL
for undisturbed samples measured for total fecal coliform (Table 5A). The lowest
percent exceedance of 400 cfus/100mL was 55.6% at Paces River, while the
highest percent exceedance was 90% at Stoney 1. Throughout the sampling
period, the minimum total fecal coliform colonies between all individual sites was
0 cfus/100 mL which was observed at Lexington, while the maximum was 3300
cfus/100 mL which was at Paces River. The minimum mean ± SE for
undisturbed total fecal coliform samples was 820.00 ± 189.62 cfus/100mL at
Riverview and 820.00 ± 232.76 at Lexington. The maximum mean ± SE was
990.00 ± 192.33 cfus/100mL at Stoney 2.
Disturbed samples measured for total fecal coliform also had greater than
25% exceedance of 400 cfus/100mL for all individual sites (Table 5B). Stoney 2
had all disturbed samples (100%) exceed 400 cfus/100mL of total fecal coliform
colonies. The minimum total fecal coliform between all individual sites was 200
cfus/100 mL which was observed at Paces River and Stoney 1. The maximum
was 6400 cfus/100 mL which was observed at Stoney 2. The minimum mean ±
SE for disturbed total fecal coliform samples was 833.33 ± 184.84 cfus/100mL
found at Paces River, while the maximum mean ± SE was 1970.00 ± 529.58
cfus/100mL at Stoney 2.
41
Table 5. Summary statistics for total fecal coliform (cfus/ 100 mL) concentrations
for each sampling site on Hidden Creek where n = 10 for all sites, except Paces
River (case on September 19, 2014 excluded from analysis). % Exceedance is
the percentage of samples for each site that exceed 400 cfus/ 100 mL (standard
set by Clean Water Act).
A. Undisturbed Total Fecal Coliform
Site Name Mean ± SE Min Max % Exceedance
Paces River 788.89 ± 319.05 200
3300 55.6%
Lexington 820.00 ± 232.76 0 2200 50%
Riverview 820.00 ± 189.62 100 2000 80%
Stoney 1 850.00 ± 141.62 100 1700 90%
Stoney 2 990.00 ± 192.325 200 2300 80%
B. Disturbed Total Fecal Coliform
Site Name Mean Min Max % Exceedance
Paces River 833.33 ± 184.84 200 2000 66.7%
Lexington 1410.00 ± 409.73 400 4900 90%
Riverview 1010.00 ± 179.78 300 1700 90%
Stoney 1 1250.00 ± 236.76 200 2700 90%
Stoney 2 1970.00 ± 529.58 700 6400 100%
42
Percent Exceedance of E.coli and Total Fecal Coliform for Hidden Creek
The final calculation performed looked at all of the sites together (Table 6).
The data showed that, in Hidden Creek, E. coli and total fecal coliform, for both
undisturbed and disturbed samples, had greater than 25% of the samples
exceed the standards. The lowest percent exceedance was 71.4% (undisturbed
total fecal coliform) and the highest percent exceedance was 89.8% (disturbed E.
coli).
Table 6. % Exceedance of fecal bacteria for all of the sites combined (n =49 for
each category). % Exceedance for E. coli is the percentage of samples across all
sites that exceed 235 cfus/ 100 mL. % Exceedance for total fecal coliform is the
percentage of samples across all sites that exceed 400 cfus/ 100 mL (standard
set by Clean Water Act).
Undisturbed E. coli
Disturbed E. coli Undisturbed Total Fecal Coliform
Disturbed Total Fecal Coliform
% Exceedance
73.5%
89.8%
71.4%
87.8%
43
DISCUSSION
The relationships between fecal coliform and abiotic factors in the water
are still not fully understood. This study demonstrated that during the summer
season, dissolved oxygen, water temperature, and turbidity were not able to
predict E. coli or total fecal coliform colonies in Hidden Creek. However, there
have been studies that have demonstrated a relationship between these abiotic
factors and fecal coliform levels. Faust et al. (1975) used a regression analysis
and observed that 75.6% of the variance in E. coli survival can be explained by
water temperature, DO, and salinity in an estuarine environment. In that model,
temperature was the most important factor and it accounted for 71.7% of the
variation in E. coli alone (Faust et al. 1975). Survival of the fecal bacteria was
negatively correlated with increasing water temperature and is in accordance
with later studies that also demonstrated an inverse relationship between
decreasing temperatures and increased survival of fecal bacteria (Faust et al.
1975; Faust 1982; Flint 1987; Garzio-Hadzick et al. 2010). When dissolved
oxygen was added to the model, the variation that could be explained by the
model increased by only 3.1% (Faust et al. 1975).
Another study on the Chattahoochee River near Atlanta, Georgia
discovered that 76% of the variability in E. coli colony numbers could be
explained by the variation in turbidity, water temperature, and stream flow events
(Lawrence 2008).
44
Both of those studies demonstrated that the three factors used in this
thesis, water temperature, DO, and turbidity, could be predictors for fecal
bacteria. However, the designs of these studies were different than this thesis.
Lawrence (2008) collected and analyzed over 8 years of data, while this study
was only concerned with one season. On the other hand, Faust (1975) collected
their data on E. coli survival using controlled laboratory experiments. I
hypothesize that my study was did not find a significant relationship between
fecal bacteria with water temperature, DO, and turbidity because the data were
taken over a short period and the natural variation within the three predictor
factors was too small (Table 7) . For example, over the whole summer season,
the range in water temperatures was 5.7 °C and the range in turbidity was 16.7
NTUs. This small variation makes it difficult to use turbidity, water temperature,
and DO to predict E. coli and total fecal coliform colonies. In addition, the 10
samples from each site may have been too few to show a cause-effect
relationship. Collecting more data on Hidden Creek over years could allow for a
significant model to be developed.
45
Table 7. Mean ± SE of water temperature (ºC), turbidity (NTUs), and DO (mg/L) for Hidden Creek taken from June 30 – September 18, 2014.
Water Quality Parameter Mean ± SE
Water Temperature (ºC) 24.68 ± 0.24
DO (mg/L) 5.11 ± 0.14
Turbidity (NTUs) 12.86 ± 0.53
Many studies have been able to determine that fecal bacteria can persist
and survive in stream sediments, but the basis for the persistence is not fully
understood. In stream sediment, E. coli concentrations are much higher than in
the overlying water column (Matson et al. 1978; Stephenson & Rychert 1982;
Benjamin et al. 2013). Stephenson and Rychert (1982) showed that E. coli
concentrations in stream sediment can range from 2 to 760 times greater than in
the overlying water and Matson et al. (1978) discovered that fecal bacteria
counts in sediment were 2,500 times greater than overlying water. Sediment
seems to present a more favorable chemical and biological environment for fecal
bacteria to persist and it is a more stable environment than the water column.
Relevant factors making it a more hospitable environment for fecal bacteria
include access to nutrients and organic matter, protection from UV light, and
protection from predators (Burton et al. 1987; Sherer et al. 1992; Davies et al.
1995; Jamieson et al. 2005; Pachepsky & Shelton 2011).
The amount of nutrients and organic matter seems to be the most
46
important factor contributing to fecal bacteria survival (Haller et al. 2009; Pote et
al. 2009). An experiment by Haller et al. (2009) used microcosms containing lake
water and different sediment types to determine what environments E. coli
survive in best. They discovered that in sediments with high organic matter and
nutrients and small grain size, E. coli had higher growth and lower decay rates
(Haller et al. 2009). The specific organic components and nutrients that are the
most important to E. coli survival have not been identified
From the data obtained, Riverview and Stoney Point 2 were the only sites
that had significantly different E. coli colony counts (Table 2). For both
undisturbed and disturbed samples, Riverview had the lowest mean ± SE for E.
coli colony counts (undisturbed: 411.11 ± 111.11; disturbed: 466.67 ± 55.28),
while Stoney 2 had the highest mean ± SE for E. coli colony counts (undisturbed:
844.44 ± 158.21; disturbed: 1088.89 ± 193.97). There was no significant
difference in total fecal coliform colonies across the sites. Therefore, it is not
possible to choose a particular site that is the main source or area of concern for
Hidden Creek; all of the sites had high levels of fecal bacteria at some point.
This thesis study suggests that typical grab samples from the water
column do not give an accurate depiction of the fecal situation in the stream. The
stream sediment can easily be disturbed by animals, storms, or humans which
can lead to an elevated number of fecal bacteria in that area. Some studies have
attempted to predict resuspension, but the systems prove to be too variable to
47
follow the models (Kim et al. 2010; Pandey et al. 2012; Piorkowski et al. 2013).
For example, storm events are a big issue because they can cause increased
resuspension of fecal bacteria in streams and also increased input of fecal
bacteria from stream bank sediment which is why nonpoint source pollutants for
fecal bacteria are so difficult to locate and control (Sadeghi & Arnold 2004). For
urban areas, such as Hidden Creek, most inputs of fecal bacteria come from
pets, wildlife, urban stormwater runoff, and leaky sewer pipes (Sadeghi & Arnold
2004).
The data collected for Hidden Creek indicate that the sediment is creating
a hospitable, stable environment where fecal bacteria can persist. Therefore,
simply taking grab samples may give a biased view of the stream and affect the
monitoring program that is developed. In addition, the data were collected during
dry sampling conditions. This is alarming because the data already exceed the
standards for undisturbed E. coli and total fecal coliform samples by a large
percentage (Table 6). It has been demonstrated that after rainfall events, a
dramatic increase in fecal coliform can be observed (Jamieson et al. 2003; Craig
et al. 2004; Piorkowski et al. 2013).
Another important point to be aware of is that the E. coli and total fecal
coliform numbers were variable throughout the season for each site (Tables 4 &
5). Sampling one day may not give the full picture of what is happening at the
site. For example, the Lexington site had one day when the total fecal coliform
48
colony count was 0 cfus/100mL, but another day it was 2,200 cfus/100mL. This
is a huge range which makes it very difficult to decide how to create a
management plan for this area. Due to few resources and limited time, most
companies and municipalities sample one time and use those data to develop a
management plan. This may cause these companies and municipalities to waste
time and money on a plan that can’t solve the problem because inadequate
preliminary data were collected.
49
CONCLUSION
This study highlights the importance of understanding fecal bacteria
persistence and variability when developing watershed management programs
for a stream. Specifically for Hidden Creek, it emphasizes the seriousness of this
stream’s fecal bacteria problem. Hidden Creek flows directly into the Catawba
River where many recreational activities such as kayaking, swimming, and
fishing occur. These high fecal bacteria numbers create an increased risk of
illness for humans using the water. The data obtained from this study indicated
that there was no specific site that can be pinpointed as the source of fecal
bacteria. Because of this, the city will be required to continue monitoring on
Hidden Creek to determine any areas of illicit discharge or if additional sampling
points are required. Once an area or areas has been determined as a main
source of fecal bacteria, the city will have to develop a management plan to
decrease the fecal bacteria by 19%.
This study contributes to the understanding of the persistence of fecal
bacteria in stream sediment and how fecal bacteria relate to other abiotic factors
in the water. It emphasizes how variable fecal bacteria are over one season and
how variable they are between sites on the same stream. It highlights the
importance of proper sampling techniques when trying to get an accurate
depiction of fecal bacteria in a stream.
50
LITERATURE CITED
3M™ Petrifilm™ EC Plates. Interpretational Guide.
http://www.3m.com/intl/kr/microbiology /p_ecoli/use3.pdf.
Allan, J.D. 2004. Landscapes and riverscapes: the influence of land use on
stream ecosystems. Annual Review of Ecology, Evolution, and Systematics
35:257-284.
American Public Health Association (APHA), American Water Works Association
(AWWA) & Water Environment Federation. 1999. Standard Methods for the
Examination of Water and Wastewater.
http://www.umass.edu/tei/mwwp/acrobat/sm9010-40intro.pdf.
Barbour, M. T., C. Faulkner, and J. Gerritsen. 1999. Rapid bioassessment
protocols for use in streams and wadeable rivers: periphyton, benthic
macroinvertebrates, and fish. Second Edition. EPA 841-B-99-002. U.S.
Environmental Protection Agency; Office of Water; Washington, D.C.
http://zoology.okstate.edu/zoo_lrc/biol1114/study_guides/labs/lab12/gen_usepa_
barbouretal_1999_rba.pdf.
Booth, D.B., D. Hartley, and R. Jackson. 2002. Forest cover, impervious-surface
area, and the mitigation of stormwater impacts. Journal of the American Water
Resources Association 38:835-845.
Booth, D.B. 1991. Urbanization and the natural drainage system—impacts,
solutions, and prognoses. Northwest Environmental Journal 7:93-118.
Brabec, E., S. Schulte, and P.L. Richards. 2002. Impervious surfaces and water
quality: a review of current literature and its implication for watershed planning.
Journal of Planning Literature 16:499-515.
Burton, G.A., D. Gunnison, and G.R. Lanza. 1987. Survival of pathogenic
bacteria in various freshwater sediments. Applied and Environmental
Microbiology 53:633-638.
Carpenter, S.R., N.F. Caraco, D.L. Correll, R.W. Howarth, A.N. Sharpley, and
V.H. Smith. 1998. Nonpoint pollution of surface water with phosphorus and
nitrogen. Ecological Applications 8:559-568
51
Census Bureau. 2010. Urban and rural classification and urban area criteria.
United States. http://www.census.gov/geo/reference/ua/urban-rural-2010.html.
Central Intelligence Agency. 2014. The World Fact Book.
https://www.cia.gov/library/publications/the-world-factbook/geos/us.html
Cho, K.H., Y.A. Pachepsky, J.H. Kim, A.K. Guber, D.R. Shelton, and R. Rowland.
2010. Release of Escherichia coli from the bottom sediment in a first-order creek:
Experiment and reach-specific modeling. Journal of Hydrology 391:322-332.
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, p. 91.
Clark, M.L. and J.R. Norris. 2000. Occurrence of fecal coliform bacteria in
selected streams in Wyoming, 1990-1999. USGS Water-Resources
Investigations Report 00-4198. Pubs.usgs.gov/wri/wri004198/.
Craig, D.L., H.J. Fallowfield, and N.J. Cromar. 2004. Use of microcosms to
determine persistence of Escherichia coli in recreational coastal water and
sediment and validation with in situ measurements. Journal of Applied
Microbiology 96:922-930.
David, M.M. and B.E. Haggard. 2011. Development of regression-based models
to predict fecal bacteria numbers at select sites within the Illinois River
Watershed, Arkansas and Oklahoma, USA. Water Air Soil Pollution 215:525-547.
Davies, C.M., J.A.H. Long, M. Donald, and N.J. Ashbolt. 1995. Survival of fecal
microorganisms in marine and fresh-water sediments. Applied and
Environmental Microbiology 61:1888-1896.
Davies, C.M. and L.M. Evison. 1991. Sunlight and the survival of enteric bacteria
in natural waters. Journal of Applied Bacteriology 70: 265-274.
EPA. 2012. Recreational Water Quality Criteria. Office of Water. 820-F-12-058. http://water.epa.gov/scitech/swguidance/standards/criteria /health/recreation /upload/RWQC2012.pdf. EPA. n.d.a. Impaired Waters and Total Maximum Daily Loads. http://water.epa.gov/lawsregs/lawsguidance/cwa/tmdl/.
52
EPA. n.d.b. 5.2 Dissolved Oxygen and Biochemical Oxygen Demand. Water: Monitorring and Assessment. http://water.epa.gov/type/rsl/monitoring/vms52.cfm.
EPA. n.d.c. Fecal Coliforms. Water: Monitorring & Assessment Section 5.11. http://water.epa.gov/typ /rsl/monitoring/vms511.cfm.
Faust, M.A., A.E. Aotaky, and M.T. Hargadon. 1975. Effect of physical parameters on the in situ survival of Escherichia coli MC-6 in an estuarine environment. Applied Microbiology 30: 800-806.
Faust, M.A. 1982. Relationship between land-use practices and fecal bacteria in soil. Journal of Environmental Quality 11:141-146.
Flint, K.P. 1987. The long-term survival of Escherichia coli in river waters. Journal of Applied Bacteriology 63:261-270.
Garzio-Hadzick, A., D.R. Shelton, R.L. Hill, Y.A. Pachepsky, A.K. Guver, and R. Rowland. 2010. Survival of manure-borne E. coli in streambed sediment: Effects of temperature and sediment properties. Water Research 44:2753-2762
Gannon, J., M. Busse, and J. Schillinger. 1983. Fecal coliform disappearance in a river impoundment. Water Research 17:1595-1601.
Hach DR/4000. Method 10049 UV Direct Reading Method. Procedure for Nitrate. www.hach.com. Hach DR/4000. Method 10071 Persulfate Digestion Method. Procedure for Total Nitrogen. www.hach.com.
Hach DR/4000. Method 8114 Molybdovanadate Method. Procedure for Phosphate. www.hach.com.
Hach DR/4000. Method 8190 PhosVer 3 with Acid Persulfate Digestion. Procedure for Total Phosphorus. www.hach.com.
Hach. 1997. Water Analysis Handbook, 3rd ed. Hach Company. Loveland, Colorado, USA.
Haller, L., E. Amedegnato, J. Poté, and W. Wildi. 2009. Influence of freshwater sediment characteristics on persistence of fecal indicator bacteria. Water, Air, and Soil Pollution 10.1007/s11270-009-0005-0.
53
Hauer, F. Richard., and G.A. Lamberti. 1996. Methods in Stream Ecology. San Diego: Academic Press.
Howell, J.M., M.S. Coyne, and P.L. Cornelius. 1996. Effect of sediment particle size and temperature on fecal bacteria mortality rates and the fecal coliform/ fecal streptococci rate. Plant and Soil Sciences Faculty Publication. Paper 12. University of Kentucky. http://uknowledge.uky.edu/pss_facpub/12.
Jamieson, R., D. Joy, H. Lee, R. Kostaschuk, and R. Gordon. 2005. Transport and deposition of sediment-associated Escherichia coli in natural streams. Water Research 39:2665-2675.
Jamieson, R.C., D.M. Joy, H. Lee, R. Kostaschuk, and R.J. Gordon. 2003. Persistence of enteric bacteria in alluvial streams. Journal of Environmental Engineering Science 3:203-212.
Kim, J.W., Y.A. Pachepsky, D.R. Shelton, and C. Coppock. 2010. Effect of streambed bacteria release on E. coli concentrations: monitoring and modeling with the modified SWAT. Ecological Modelling 221:1592-1604.
Konrad, C.P and D.B. Booth. 2005. Hydrologic Changes in Urban Streams and their Ecological Significance. American Fisheries Society 47:157-177.
Lawrence, S. 2008. Escherichia coli bacteria density in relation to turbidity, streamflow characteristics, and season in the Chattahoochee River near Atlanta, Georgia, October 2000 through September 2008—Description, statistical analysis, and predictive modeling. Scientific Investigations Report 2012-5037. USGS. http://pubs.er.usgs.gov/publication/sir20125037.
Leblanc, R.T., R.D. Brown, and J.E. Fitzgibbon. 1997. Modeling the effects of land use change on water temperature in unregulated urban streams. Journal of Environmental Management 49:445-69.
Mallin, M.A., K.E. Williams, E.C. Esham, and R.P. Lowe. 2000. Effect of human development on bacteriological water quality in coastal watershed. Ecological Application 10:1047-1056.
Matson, E.A., S.G. Hornor, and J.D. Buck. 1978. Pollution indicators and other microorganisms in river sediment. Journal of Water Pollution Control Federation 50:13-19.
54
Marti, E., J. Aumatell, L. Gode, M. Poch, and F. Sabater. 2004. Nutrient retention efficiency in streams receiving inputs from wastewater treatment plants. Journal of Environmental Qual. 33:285-293.
McFeters, G.A. and D.G. Stuart. 1972. Survival of coliform bacteria in natural waters: field and laboratory studies with membrane-filter chambers. American Society for Microbiology 24:805-811.
Muirhead, R.W., R.J. Davies-Colley, A.M. Donnison, and J.W. Nagels. 2004. Faecal bacteria yield in artificial flood events: quantifying in-stream stores. Water Research 38:1215-1224. Nevers, M.B. and R.L. Whitman. 2005. Nowcast modeling of Escherichia coli concentrations at multiple urban beaches of southern Lake Michigan. Water Research 39:5250-5260.
Ometo, J.P.H.B, L.A. Martinelli, M.V. Ballester, A. Gessner, A. Krusche, R.L. Victoria, R.L, M. Williams. 2000. Effects of land use on water chemistry and macroin- vertebrates in two streams of the Piracicaba River Basin, southeast Brazil. Freshwater Biology 44:327-37.
Paaijmans, K.P., W. Takken, A.K. Githeko, and A.F. Jacobs. 2008. The effect of water turbidity on the near-surface water temperature of larval habitats of the malaria mosquito Anopheles gambiae. International Journal of Biometeorology 8:747-753.
Pachepsky, Y. A., and D.R. Shelton. (2011). Escherichia coli and fecal coliforms in freshwater and estuarine sediments. Critical Reviews in Environmental Science and Technology 41: 1067-1110.
Pandey, P.K., M.L. Soupir, and C.R. Rehmann. 2012. A model for predicting resuspension of Escherichia coli from streambed sediments. Water Research 46:115-126.
Paul, M. J. and J.L. Meyer. 2001. Streams in the urban landscape. Annual Review of Ecology and Systematics 32:333-365.
Piorkowski, G.S., R. C. Jamieson, L.T. Hansen, G.S. Bezanson, and C.K. Yost. 2013. Characterizing spatial structure of sediment E. coli populations to inform sampling design. Environmental Monitoring and Assessment 10.1007/s10661-013-3373-2.
55
Pluhowski, E. J. 1970. Urbanization and its effect on the temperature of the streams on Long Island, New York. Geological Survey Professional Paper 627-D. United States Government Printing Office, Washington. http://pubs.usgs.gov/pp/0627d/report.pdf. Porcella, D.B. and D.L. Sorensen. 1980. Characteristics of non-point source urban runoff and its effects on stream ecosystems. EPA-600/3- 80-032. Washington, DC: EPA.
Poté, J., L. Haller, R. Kottelat, V. Sastre, P. Arpagaus, and W. Wildi. 2009. Persistence and growth of faecal culturable bacterial indicators in water column and sediments of Vidy Bay, Lake Geneva, Switzerland. Journal of Environmental Science 21: 62-69.
Sadeghi, A.M. and J.G. Arnold. 2004. A SWAT/Microbial Sub-Model for Predicting Pathogen Loadings in Surface and Groundwater at Watershed and Basin Scales. In: Proceedings of International Workshop on: Identification of Current Status and Needs of GIS and Database Technology in the Agricultural Sector - GIS for Analysis and Monitoring of Land Use and Land/Water Quality, March 4-6, 2004, Pulawy, Poland, Chapter VIII, p. 1-10.
Schoonover, J.E., B.G. Lockaby, and S. Pan. 2005. Changes in chemical and
physical properties of stream water across an urban-rural gradient in western
Georgia. Urban Ecosystems 8:107-124.
Sinton, L.W., C.H. Hall, P.A. Lynch, and R.J. Davies-Colley. 2002. Sunlight inactivation of fecal indicator bacteria and bacteriophages from waste stabilization pond effluent in fresh and saline waters. Applied and Environmental Microbiology 68:1122-1131.
Sherer, B.M., J. R. Miner, J.A. Moore, and J.C. Buckhouse. 1992. Indicator bacterial survival in stream sediments. Journal of Environmental Quality 21:591-595.
South Carolina Department of Health & Environmental Control (SCDHEC).
2012. Watershed Water Quality Assessment: Catawba River Basin.
https://www.scdhec.gov/environment/ water/shed/docs/catawba.pdf.
South Carolina Department of Health & Environmental Control (SCDHEC). 1999. Total Maximum Daily Load Development for unnamed tributary to Catawba River CW-221. Bureau of Water.
56
Stephenson, G.R. and R.C. Rychert. 1982. Bottom sediment: a reservoir of
Escherichia coli in rangeland streams. Journal of Range Management 35:119-
123.
Vidon, P., L.P. Tedesco, J. Wilson, M.A. Campbell, and L.R. Casey. 2008. Direct and indirect hydrological controls on E. coli concentration and loading in Midwestern streams. Journal of Environmental Quality 37:1761-1768.
Walsh, C.J., A.H. Roy, J.W. Feminella, P.D. Cottingham, P.M. Groffman, and
R.P. Morgan II. 2005. The urban stream syndrome: current knowledge and the
search for a cure. The North American Benthological Society 24:706-723.
Wenger, S.J., A.H. Roy, C.R. Jackson, E.S. Bernhardt, T.L. Carter, S. Filosos,
C.A. Gibson, W.C. Hession, S.S. Kaushal, E. Marti, J.L. Meyer, M.A. Palmer,
M.J. Paul, A.H. Purcell, A. Ramirez, A.D. Rosemond, K.A. Schofield, E.B.
Sudduth, and C.J. Walsh. 2009. Twenty-six key research question in urban
stream ecology: an assessment of the state of the science. Journal of the North
American Benthological Society 28:1080-1098.
Wickham, J.D., M.S. Nash, T.G. Wade, and L. Currey. 2006. Statewide empirical
modeling of bacterial contamination of surface waters. Journal of American
Water Resource Association 42:583-591.
Wilkinson, J., A. Jenkins, M. Wyer, and D. Kay. 1995. Modelling faecal coliform
dynamics in streams and rivers. Water Research 29:847-855.
Winter J. G., and H.C.Duthie. 2000. Export coefficient modeling to assess
phosphorus loading in an urban watershed. Journal of the American Water
Resources Association 36:1053-61.
World Bank. 2013. Population Growth (Annual %)
http://data.worldbank.org/indicator /SP.POP.GROW.
Young, K.D. and E.L. Thackston. 1999. Housing Density and Bacterial Loading in
Urban Streams. Journal of Environmental Engineering 1777-1780.