2008-2009 Final ReportNEW HANOVER COUNTY WATER QUALITY MONITORING PROGRAM
2008-2009
FINAL REPORT
Prepared by:
Coastal Planning & Engineering of North Carolina, Inc.
Marine Scientist: Brad Rosov, M.Sc.
Prepared For:
New Hanover County, North Carolina
Recommended Hume, 2009: Rosov, B., 2009. New Hanover County Water Quality Monitoring
Program: 2008-2009 Final Report. New Hanover County, North Carolina: Coastal Planning &
Engineering of North Carolina, Inc. 45p.
June 2009
COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
EXECUTIVE SUMMARY
This report represents the June 2008 through May 2009 results of the New Hanover County
Water Quality Monitoring Program. Twenty-two (22) monitoring stations within seven (7)
creeks in New Hanover County were monitored on a monthly basis for physical, chemical, and
biological parameters of water quality between June 2008 and September 2008. Due to
budgetary constraints, the scope of the program was reduced by three (3) monitoring sites for the
period between October 2008 and May 2009. The results presented in this report are described
from a watershed perspective.
In order to provide a quick-glance assessment of the water quality within a particular sampling
station and watershed, a rating system has been established for a number of parameters. This
quantitative system assigns a rating of “GOOD”, “FAIR”, or “POOR” to a sampling station
depending on the percentage of samples exceeding the State standard for dissolved oxygen,
turbidity, Chlorophyll-a, Enterococci, and fecal coliform bacteria. If the recorded value of a
parameter exceeds the State standard less than 10% of the times sampled, the station will receive
a “GOOD” rating for the parameter. A “FAIR” rating is assigned when a parameter exceeds the
State standard 11-25% of the times sampled. Parameters measured that exceed the State
standard more than 25% of the sampling times are given a “POOR” rating.
As displayed in the tables below, turbidity within all watersheds were determined to be GOOD
throughout the study period. Dissolved oxygen varied considerably between watersheds and
within sites. Specifically, Barnards Creek, Lords Creek, and Smith Creek contained good levels
of dissolved oxygen while Futch Creek and Motts Creek contained fair levels of dissolved
oxygen. Pages Creek and Prince Georges Creek contained poor dissolved oxygen levels in the
majority of its sampling sites. Chlorophyll-a was good within all watersheds and individual
sampling sites with the exception of Lords Creek, which contained two (2) samples above the
State standard resulting in a fair rating. Enterococcus, a bacteria indicator of water quality, was
examined within each site and watershed. Generally, Enterococci was problematic in a number
of these watersheds as Lords Creek, Prince Georges Creek, and Pages Creek received fair ratings
while Barnards Creek, Motts Creek, and Smith Creek received poor ratings. Only Futch Creek
contained good water quality in terms of Enterococci levels. Fecal coliform, another indicator of
bacterial contamination, was assessed monthly within Pages Creek and Futch Creek. These
creeks generally exceeded the State shellfish standard for fecal coliform bacteria resulting in
poor ratings.
Ratings by Watershed
Parameter Barnards
Creek
Futch
Creek
Lords
Creek
Motts
Creek
Pages
Creek
Prince
Georges
Creek
Smith
Creek
Turbidity GOOD GOOD GOOD GOOD GOOD GOOD GOOD
Dissolved Oxygen GOOD FAIR GOOD FAIR POOR POOR GOOD
Chlorophyll-a GOOD GOOD FAIR GOOD GOOD GOOD GOOD
Enterococci POOR GOOD FAIR POOR FAIR FAIR POOR
Fecal Coliform N/A POOR N/A N/A POOR N/A N/A
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COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
Source Tracking
As a supplement to the regular monthly water quality monitoring, a separate sampling effort was
undertaken to determine the source of bacterial contamination within Pages Creek. New
Hanover County officials funded this source tracking project in an effort to determine the origin
of bacterial contamination within two water quality monitoring stations within Pages Creek in
proximity to Bayshore Drive where high levels of bacteria have been documented.
Four sampling events were conducted through the course of this study; two (2) during dry
periods and two (2) during rain events. Genetic analysis of samples collected from both sites
indicated the presence of human fecal bacteria within these locations in Pages Creek. Other
sources of contamination were shown to be derived from ruminants such as horses. Furthermore,
the presence of optical brighteners, a chemical compound often found in laundry detergents,
indicates that either sewage or septic system leachate is polluting the creek waters. In
conclusion, the results of this project suggest that a portion of the bacterial load entering Pages
Creek during this study originated from human sources. There is a strong likelihood that failing
sewer or septic tank infrastructure within the area may be contributing to the problem.
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NEW HANOVER COUNTY WATER QUALITY MONITORING PROGRAM
FINAL REPORT
Table of Contents
Introduction ........................................................................................................................................1
Parameters .......................................................................................................................................4
Standards .........................................................................................................................................6
Methods..............................................................................................................................................9
Physical Parameters ........................................................................................................................9
Chemical and Biological Parameters ..............................................................................................9
Results ................................................................................................................................................9
Rating System .................................................................................................................................10
Barnards Creek ................................................................................................................................10
Futch Creek .....................................................................................................................................13
Lords Creek .....................................................................................................................................19
Motts Creek .....................................................................................................................................21
Pages Creek .....................................................................................................................................26
Prince Georges ................................................................................................................................30
Smith Creek ....................................................................................................................................34
Comprehensive Rating by Watershed .............................................................................................39
Source Tracking ..............................................................................................................................40
Rainfall and Enterococci Levels .....................................................................................................40
Discussion ..........................................................................................................................................41
Literature Cited ................................................................................................................................44
List of Figures
Figure No.
1 Map of New Hanover County and watersheds included in this study ...................................3
2 Water Quality Sites within the Barnards Creek Watershed ...................................................11
3 Dissolved Oxygen at BC-CBR ..............................................................................................12
4 Dissolved Oxygen at BC-RR .................................................................................................12
5 Enterococci at BC-CBR .........................................................................................................12
6 Enterococci at BC-RR ...........................................................................................................13
7 Water Quality Sites within the Futch Creek Watershed ........................................................14
8 Dissolved Oxygen at FC-4 ..................................................................................................... 15
9 Dissolved Oxygen at FC-6 ..................................................................................................... 16
10 Dissolved Oxygen at FC-8 ..................................................................................................... 16
11 Dissolved Oxygen at FC-13 ................................................................................................... 16
12 Dissolved Oxygen at FC-FOY ............................................................................................... 17
13 Enterococci and Fecal Coliform at FC-4 ............................................................................... 17
14 Enterococci and Fecal Coliform at FC-6 ............................................................................... 17
15 Enterococci and Fecal Coliform at FC-8 ............................................................................... 18
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NEW HANOVER COUNTY WATER QUALITY MONITORING PROGRAM
FINAL REPORT
Table of Contents (cont'd)
List of Figures
Figure No.
16 Enterococci and Fecal Coliform at FC-13 .........................................................................18
17 Enterococci and Fecal Coliform at FC-FOY .....................................................................18
18 Water Quality Site within the Lords Creek Watershed .....................................................20
19 Dissolved Oxygen at LC-RR .............................................................................................21
20 Enterococci at LC-RR ........................................................................................................21
21 Water Quality Sites within the Motts Creek Watershed ....................................................23
22 Dissolved Oxygen at MOT-CBR .......................................................................................24
23 Dissolved Oxygen at MOT-ND .........................................................................................24
24 Dissolved Oxygen at MOT-RR .........................................................................................24
25 Enterococci and Fecal Coliform at MOT-CBR .................................................................25
26 Enterococci and Fecal Coliform at MOT-ND ...................................................................25
27 Enterococci and Fecal Coliform at MOT-RR ....................................................................25
28 Water Quality Sites within the Pages Creek Watershed ....................................................27
29 Dissolved Oxygen at PC-BDDS ........................................................................................28
30 Dissolved Oxygen at PC-BDUS ........................................................................................28
31 Dissolved Oxygen at PC-M ...............................................................................................28
32 Enterococci and Fecal Coliform at PC-BDUS ..................................................................29
33 Enterococci and Fecal Coliform at PC-BDDS ..................................................................29
34 Enterococci and Fecal Coliform at PC-M .........................................................................29
35 Water Quality Sites within the Prince Georges Creek Watershed .....................................31
36 Dissolved Oxygen at PG-CH .............................................................................................32
37 Dissolved Oxygen at PG-ML.............................................................................................32
38 Dissolved Oxygen at PG-NC .............................................................................................32
39 Enterococci and Fecal Coliform at PG-CH .......................................................................33
40 Enterococci and Fecal Coliform at PG-ML .......................................................................33
41 Enterococci and Fecal Coliform at PG-NC .......................................................................33
42 Water Quality Sites within the Smith Creek Watershed ....................................................35
43 Dissolved Oxygen at SC-23 ...............................................................................................36
44 Dissolved Oxygen at SC-CD .............................................................................................36
45 Dissolved Oxygen at SC-CH .............................................................................................36
46 Dissolved Oxygen at SC-GR .............................................................................................37
47 Dissolved Oxygen at SC-NK .............................................................................................37
48 Enterococci at SC-23 .........................................................................................................37
49 Enterococci at SC-CD ........................................................................................................38
50 Enterococci at SC-CH ........................................................................................................38
51 Enterococci at SC-GR ........................................................................................................38
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NEW HANOVER COUNTY WATER QUALITY MONITORING PROGRAM
FINAL REPORT
Table of Contents (cont'd)
List of Figures
Figure No.
52 Enterococci at SC-NK ........................................................................................................... 39
53 Percent of impervious surface coverage within New Hanover County watersheds ...............43
List of Tables
Table No.
1 List of Sampling Sites ............................................................................................................2
2 North Carolina Water Quality Standards ...............................................................................7
3 Single sample standards for Enterococci as determined by the US EPA ..............................7
4 Single sample standards for Enterococci as determined by the NC DENR Recreational
Water Quality Program .....................................................................................................8
5 Proposed Tier Classification for New Hanover County Water Quality Monitoring
Sampling Sites ..................................................................................................................8
6 Mean values of select parameters from Barnards Creek .......................................................11
7 Ratings of parameters within sampling stations within Barnards Creek ...............................13
8 Mean values of select parameters from Futch Creek .............................................................15
9 Ratings of parameters within sampling stations within Futch Creek ....................................19
10 Mean values of select parameters from Lords Creek .............................................................20
11 Ratings of parameters within sampling stations within Lords Creek ....................................21
12 Mean values of select parameters from Motts Creek .............................................................23
13 Ratings of parameters within sampling stations within Motts Creek ....................................26
14 Mean values of select parameters from Pages Creek .............................................................27
15 Ratings of parameters within sampling stations within Pages Creek ....................................30
16 Mean values of select parameters from Prince Georges Creek .............................................31
17 Ratings of parameters within sampling stations within Prince Georges Creek .....................34
18 Mean values of select parameters from Smith Creek ............................................................35
19 Ratings of parameters within sampling stations within Smith Creek ....................................39
20 Ratings of parameters within each watershed ........................................................................39
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FINAL REPORT
Table of Contents (cont'd)
List of Appendices
Appendix No.
A Photographs of Sampling Sites
B Raw Data
C Source Tracking Report
INTRODUCTION
The creeks in New Hanover County, North Carolina provide a wide range of recreational
activities for thousands of local citizens and visiting tourists each year. Tidal creeks are rich
areas in terms of aquatic, terrestrial and avian wildlife and can support complex food webs
(Odum et al, 1984; Kwak and Zedle, 1997). Protection of the water quality within these creeks is
a high priority for New Hanover County. As growth and development continue within the City
of Wilmington and the County, water quality has been increasingly threatened due to many
factors including aging infrastructure, increased impervious surface area and subsequent
stormwater runoff. To address these issues, the County has administered a long-standing water
quality monitoring program since 1993 designed to assess the water quality within the creeks
located within the County.
Coastal Planning & Engineering of North Carolina, Inc. began monitoring seven (7) tidal creeks
within New Hanover County on a monthly basis beginning in November 2007. The information
presented in this report represents the results of this monitoring between the months of June 2008
and May 2009. The creeks included in this study are Pages and Futch Creek, which drain into
the Atlantic Intracoastal Waterway (ICW) and Lords, Motts, Barnards, Smith, and Prince
Georges Creek, which drain into the Cape Fear River (Table 1). Due to funding limitations, the
total number of monitoring sites within these seven (7) creeks was reduced from twenty-two (22)
to nineteen (19) between the months of October 2008 and May 2009. Fifteen (15) of the twenty-
two (22) sampling sites were previously monitored by the University of North Carolina at
Wilmington. In order to assess any changes to historical trends within individual sites and entire
watersheds, data provided by UNCW has been analyzed and incorporated into the results and
discussion section of this report.
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Table 1. List of Sampling Sites
Creek Name Site Name Site Code Latitude Longitude
Motts Creek Carolina Beach Road MOT-CBR 34° 08.610 77° 53.830
Motts Creek Normandy Drive MOT-ND 34° 08.373 77° 54.580
Motts Creek River Road MOT-RR 34° 07.752 77° 54.966
Lords Creek River Road LC-RR 34° 05.185 77° 55.275
Barnards Creek Carolina Beach Road BC-CBR 34° 09.522 77° 54.712
Barnards Creek River Road BC-RR 34° 09.525 77° 56.281
Smith Creek Castle Hayne Road SC-CH 34° 15.541 77° 56.325
Smith Creek 23rd Street SC-23 34° 15.472 77° 55.178
Smith Creek Candlewood Drive SC-CD 34° 17.438 77° 51.332
Smith Creek North Kerr SC-NK 34° 15.744 77° 53.256
Smith Creek Gordon Road SC-GR 34° 16.639 77° 52.037
Prince Georges Creek Marathon Landing PG-ML 34° 21.088 77° 55.349
Prince Georges Creek Castle Hayne Road PG-CH 34° 20.675 77° 54.217
Prince Georges Creek North College PG-NC 34° 20.331 77° 53.607
Futch Creek 4 FC-4 34° 18.068 77° 44.760
Futch Creek 6 FC-6 34° 18.178 77° 45.038
Futch Creek 8 FC-8 34° 18.25 77° 45.222
Futch Creek 13 FC-13 34° 18.214 77° 45.451
Futch Creek Foy Branch FC-FOY 34° 18.405 77° 45.358
Pages Creek Mouth PC-M 34° 16.209 77° 46.270
Pages Creek Bayshore Drive Down Stream PC-BDDS 34° 16.685 77° 47.673
Pages Creek Bayshore Drive Up Stream PC-BDUS 34° 16.623 77° 48.104
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COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
Figure 1. Map of New Hanover County and watersheds included in this study
The State of North Carolina has employed a series of classifications that apply to all waters in
the State including streams, rivers, and lakes (NC Administrative Code, section 15A NCAC 2B
.0200). These classifications are meant to protect the specified uses within waterbodies. These
include aquatic life survival and reproduction, secondary recreation, primary recreation,
shellfishing, and water supply. The classifications that apply to the creeks examined in this
study are:
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COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
C Sw: Freshwater that is protected for aquatic life and secondary recreation uses. The
“Sw” supplemental classification indicates that these are swamp waters, and so are likely
to have lower dissolved oxygen and pH than non-swamp streams due to natural
conditions. However, a majority of the sites, including Lords Creek, Motts Creek,
Barnards Creek, Smith Creek, and Prince Georges Creek, designated as C Sw by the
State, are tidally influenced and have a brackish salinity range.
SA: Saline water bodies that are protected for shellfishing uses. This use requires a more
stringent standard for fecal coliform. Areas protected for shellfishing are also subject to
the protection requirements for the less stringent classifications of SC and SB, which
include aquatic life, secondary recreation, and primary recreation. This designation
applies to Futch Creek and Pages Creek.
Parameters
Physical, chemical, and biological water quality monitoring data are currently being collected for
this study. Physical parameters include temperature, salinity, conductivity, pH, turbidity, and
dissolved oxygen. Chemical parameters monitored in this study include orthophosphate and
nitrate/nitrite. Biological parameters include Chlorophyll-a and two suites of fecal indicator
bacteria: Enterococci and fecal coliform bacteria. Due to limited funding, fecal coliform
samples were only collected from sampling sites located within Futch Creek and Pages Creek,
with the exception of one month (April, 2009) when fecal coliform samples were collected
within Motts Creek and Prince Georges Creek as well.
Temperature:
Thermal pollution can result in significant changes to the aquatic environment. Most aquatic
organisms are adapted to survive within a specific temperature range. Thermal pollution may
also increase the extent to which fish are vulnerable to toxic compounds, parasites, and disease.
If temperatures reach extremes of heat or cold, few organisms will survive.
Thermal pollution may be caused by stormwater runoff from warm surfaces such as streets and
parking lots. Soil erosion is another cause, since it can cause cloudy conditions in a water body.
Cloudy water absorbs the sun's rays, resulting in a rise in water temperature. Thermal pollution
may even be caused by the removal of trees and vegetation which normally shade the water
body. In addition to the direct effects of thermal pollution on aquatic life, there are numerous
indirect effects. Thermal pollution results in lowered levels of dissolved oxygen, since cooler
water can hold more oxygen than warmer water.
Salinity:
Salinity is a measure of the amount of sodium chloride ions dissolved in water. This is important
to monitor since changes in the levels of salt concentration can impact the ability of salt sensitive
species to survive. An estuary, such as the lower Cape Fear River, usually exhibits a gradual
change in salinity throughout its length, as fresh water entering the estuary from tributaries mixes
with seawater moving in from the ocean. Salinity levels control, to a large degree, the types of
plants and animals that can live in different zones of the estuary. Freshwater species may be
restricted to the upper reaches of the estuary, while marine species inhabit the estuarine mouth.
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COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
Some species tolerate only intermediate levels of salinity while broadly adapted species can
acclimate to any salinity ranging from freshwater to seawater.
Conductivity:
Specific conductance is a measure of the ability of water to conduct an electrical current.
Similar to salinity, it measures the amount of dissolved ions (including sodium chloride) in the
water.
pH:
The pH of water is a measurement of the concentration of H+ ions, using a scale that ranges from
0 to 14. Natural water usually has a pH between 6.5 and 8.5. While there are natural variations
in pH, many pH variations are due to human influences. Unanticipated decreases in pH could be
indications of acid rain, runoff from acidic soils, or contamination by agricultural chemicals.
Turbidity:
Turbidity is the amount of particulate matter that is suspended in water. Turbidity measures the
scattering effect that suspended solids have on light: the higher the intensity of scattered light,
the higher the turbidity. During a rainstorm, particles from the surrounding land are washed into
the river making the water a muddy brown color, indicating higher turbidity.
Dissolved Oxygen:
Dissolved oxygen (DO) refers to the volume of oxygen that is contained in water. Oxygen enters
the water as rooted aquatic plants and algae undergo photosynthesis, and as oxygen is transferred
across the air-water interface. The amount of oxygen that can be held by the water depends on
the water temperature, salinity, and pressure.
Rapidly moving water, such as in a flowing stream, tends to contain a lot of dissolved oxygen,
while stagnant water contains little. Oxygen levels are also affected by the diurnal (daily) cycle.
Plants, such as rooted aquatic plants and algae produce excess oxygen during the daylight hours
when they are photosynthesizing. During the dark hours they must use oxygen for life processes.
Bacteria in water can consume oxygen as organic matter decays. Thus, excess organic material
in waterbodies can cause oxygen deficies. Aquatic life can become stressed or die in stagnant
water containing high levels of rotting, organic material in it, especially in summer, when
dissolved-oxygen levels are at a seasonal low.
Phosphates:
Phosphorus is a nutrient required by all organisms for the basic processes of life. Phosphorus is a
natural element found in rocks, soils and organic material. Phosphorus clings tightly to soil
particles and is used by plants, so its concentration in clean waters is generally very low.
However, phosphorus is used extensively in fertilizer and other chemicals, so it can be found in
higher concentrations in areas of human activity. High levels in the water column can be
detrimental to water quality as phosphates can cause algal blooms resulting in decreased
dissolved oxygen levels.
Orthophosphate is sometimes referred to as "reactive phosphorus." Orthophosphate is the most
stable kind of phosphate, and is the form used by plants. Orthophosphate is produced by natural
processes and is found in sewage.
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Nitrate/Nitrite:
Nitrate is highly soluble (dissolves easily) in water and is stable over a wide range of
environmental conditions. It is easily transported in streams and groundwater. Nitrates feed
plankton (microscopic plants and animals that live in water), aquatic plants, and algae, which are
then eaten by fish. Nitrite is relatively short-lived in water because it is quickly converted to
nitrate by bacteria.
Excessive concentrations of nitrate and/or nitrite can be harmful to humans and wildlife. If
excessive amounts of nitrates are added to the water, algae and aquatic plants can be produced in
large quantities. When these algae die, bacteria decompose them, and use up oxygen.
Chlorophyll-a:
Chlorophyll-a is a green pigment found in plants. It absorbs sunlight and converts it to sugar
during photosynthesis. Chlorophyll-a concentrations are an indicator of phytoplankton
abundance and biomass in coastal and estuarine waters. High levels often indicate an algal
bloom which can induce the depletion of oxygen in the water column due to the microbial
degradation of plant cells. Chlorophyll-a concentrations are often higher after rainfall,
particularly if the rain has flushed nutrients into the water. Higher chlorophyll-a levels are also
common during the summer months when water temperatures and light levels are high because
these conditions lead to greater phytoplankton numbers.
Fecal Coliform:
Fecal Coliform bacteria are present in the feces and intestinal tracts of humans and other warm-
blooded animals, and can enter water bodies from human and animal waste. If a large number of
fecal coliform bacteria are found in water, it is possible that pathogenic (disease- or illness-
causing) organisms are also present in the water. Pathogens are typically present in such small
amounts it is impractical to monitor them directly. High concentrations of the bacteria in water
may be caused by septic tank failure, poor animal keeping practices, pet waste, and urban runoff.
In order to adequately assess human health risks and develop watershed management plans, it is
necessary to know the sources of fecal contamination.
Enterococci:
Enterococci are distinguished from fecal coliform bacteria by their ability to survive in saltwater,
and in this respect they more closely mimic many pathogens than do the other indicators.
Enterococci are typically more human-specific than the larger fecal streptococcus group. EPA
recommends enterococci as the best indicator of health risk in saltwater used for recreation and
as a useful indicator in freshwater as well. In 2004, enterococci took the place of fecal coliform
as the new federal standard for water quality at public beaches. It is believed to provide a higher
correlation than fecal coliform with many of the human pathogens often found in sewage (Jin, et
al., 2004). Results indicated that enterococci might be a more stable indicator than fecal
coliform and, consequently, a more conservative indicator under brackish water conditions.
Standards
Water quality standards have been established legislatively for a number of these parameters
(Table 2). Many of the water quality standards are described in the NC Administrative Code,
section 15A NCAC 2H .0100. The water quality standards for Enterococci bacteria are
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COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
described by the US EPA (US EPA, 1986) and in the NC Administrative Code, section 15A
NCAC 18A .3402. The US EPA standards for Enterococci bacteria are based on incidents of
gastrointestinal illness following contact with bathing waters. Bacterial contamination is
quantified by “colony forming units” or CFU. Single sample maximum allowable Enterococci
density is 104 CFU/100ml, 158 CFU/100ml, 276 CFU/100ml, and 501 CFU/100ml for
designated beach areas, swimming areas with moderate to full body contact, lightly used full
body contact swimming areas, and infrequently used full body contact swimming areas,
respectively (Table 3). When at least five samples are collected within a 30 day period, the US
EPA recommends utilizing a geometric mean standard of 35 CFU/100ml. Geometric means are
often useful summaries for highly skewed data, as are often found with bacteriological datasets.
The North Carolina Recreational Water Quality Program (RWQ) adopted similar standards for
Enterococci bacteria, also determined by the frequency of swimming activity. As defined by
RWQ, Tier I swimming areas are used daily during the swimming season, Tier II swimming
areas are used three days a week during the swimming season, and Tier III swimming areas are
used on average 4 days a month during the swimming season. Single sample standards for Tiers
I, II, and III are 104 CFU/100ml, 276 CFU/100ml, and 500 CFU/100ml, respectively (Table 4).
A geometric mean of 35 CFU/100ml within Tier I swimming areas may also be utilized if at
least five samples are collected within 30 days. The creeks included in this study have not been
classified within the RWQ tier system; however an analysis of accessibility as an indicator of
swimming and boating usage has been performed (Table 5). Based on this analysis, of the
twenty-two (22) sampling sites, three (3) could be considered Tier II and nineteen (19) could be
considered Tier III.
Table 2. North Carolina Water Quality Standards
Parameter Standard for SA Waters Standard for C Sw Waters
Dissolved Oxygen 5.0 mg/l 4.0 mg/la
Turbidity 25 NTU 50 NTU
pH 6.8-8.5 6.0-9.0b
Chlorophyll-a 40.0 ug/l 40.0 ug/l
Fecal Coliform Geometric Mean (5 samples within
30 days) <14 CFU/100ml; or 10%
of samples <43 CFU/100ml
Geometric Mean (5 samples within
30 days) <200 CFU/100ml; or single
sample <400 CFU/100ml
Enterococci c Geometric Mean (5 samples within
30 days) <35 CFU/100ml
Geometric Mean (5 samples within
30 days) <35 CFU/100ml
(a) Swamp waters may have lower values if caused by natural conditions (b) For swamp streams, pH may be as low as 4.3 if caused by natural conditions
(c) See Table 4 for single sample standards based off the tiered system employed by NC DENR Recreational Water
Quality Program
Table 3. Single sample standards for Enterococci as determined by the US EPA
Single sample maximum
Designated beach areas < 104 CFU/100ml
Swimming areas with moderate full body contact < 158 CFU/100ml
Lightly used full body contact swimming areas < 276 CFU/100ml
Infrequently used full body contact swimming areas < 501 CFU/100ml
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COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
Table 4. Single sample standards for Enterococci as determined by the NC DENR
Recreational Water Quality Program
Single sample maximum
Tier I, swimming areas used daily during the
swimming season
<104 CFU/100ml
Tier II, swimming areas used three days a week
during the swimming season
<276 CFU/100ml
Tier III, swimming areas used on average four days
a month during the swimming season
<500 CFU/100ml
Table 5. Proposed Tier Classification for New Hanover County Water Quality Monitoring
Sampling Sites
Site Name
Proposed
Tier
Classification
Accessible
for
Boating or
Swimming Comments
MOT-CBR Tier III No Adjacent to culvert off Carolina Beach Road
MOT-ND Tier III No Adjacent to small bridge on Normandy Drive
MOT-RR Tier III No Adjacent to bridge on River Road
LC-RR Tier III No Adjacent to bridge on River Road
BC-CBR Tier III No Adjacent to culvert off Carolina Beach Road
BC-RR Tier III No Adjacent to bridge on River Road
SC-CH Tier III No Adjacent to bridge on Castle Hayne Road
SC-23 Tier III No Adjacent to bridge on 23rd Street
SC-CD Tier III No Narrow, shallow. Adjacent to Candlewood Drive
SC-NK Tier II Yes Small boat launch site off North Kerr
SC-GR Tier III No Adjacent to culvert on Gordon Road
PG-ML Tier III No Small boat launch site on private property
PG-CH Tier III No Adjacent to culvert on Castle Hayne Road
PG-NC Tier III No Adjacent to culvert on North College Road
FC-4 Tier III No Private docks are the only means of direct access
FC-6 Tier III No Private docks are the only means of direct access
FC-8 Tier III No Private docks are the only means of direct access
FC-13 Tier III No Private docks are the only means of direct access
FC-FOY Tier III No No clear access points (no docks on Foy branch)
PC-M Tier II Yes Direct access via docks and boat ramp at Pages Creek Marina
PC-BDDS Tier III No Private docks are the only means of direct access
PC-BDUS Tier II Yes Public boat ramp off Bayshore Drive
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COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
METHODS
The seven creeks included in this study were selected by County staff and individual sampling
sites were selected by County staff in consultation with Coastal Planning & Engineering of North
Carolina, Inc. These seven creeks are primarily located in the unincorporated portion of New
Hanover County. Sampling sites were accessed from land, generally near a bridge or culvert
crossing, or by boat. Each site was sampled one time per month during a high ebb tide. Tides
were determined utilizing the National Oceanic and Atmospheric Administration’s (NOAA)
Tides and Currents website (http://tidesandcurrents.noaa.gov/).
Due to time constraints, monthly sampling events were conducted on three subsequent days each
month. Lords Creek, Motts Creek, and Barnards Creek were visited on the first sampling day
while Smith Creek and Prince Georges Creek were visited the second day. Futch Creek and
Pages Creek were visited on the third day. Rainfall totals for the 24 hours prior to each sampling
event were obtained from observations recorded at Wilmington International Airport as reported
by NOAA’s National Weather Service web site (http://www.srh.noaa.gov/data/RAH/RTPRAH).
Physical Parameters
All physical measurements (temperature, salinity, conductivity, turbidity, dissolved oxygen, and
pH) were taken in situ utilizing a 6820 YSI Multiparameter Water Quality Probe linked to a YSI
650 MDS display unit. The YSI Probe was calibrated each day prior to use. Physical
measurements were taken from the surface at all sites (depth = 0.1m) and near the creek bottom
at sites with depths greater than 0.5m. Following each sampling trip, the YSI Probe was post-
calibrated following each sampling date to ensure that the physical parameters measured were
within an acceptable range.
Chemical and Biological Parameters
Water samples were obtained for the laboratory analysis of chemical (nitrate/nitrite and
orthophosphate) and biological (Enterococci, fecal coliform, and Chlorophyll-a) parameters.
These grab samples were collected in sterile bottles during a high ebb tide from the surface at
each site (depth = 0.1m). Water samples were placed on ice immediately following collection
and were delivered in coolers to Environmental Chemists, Inc. of Wilmington, North Carolina
for analysis. All analyses performed by Environmental Chemists, Inc. were conducted utilizing
the following standard EPA approved methods:
Orthophosphate: SM 4500E
Nitrate/Nitrite: EPA 353.2
Chlorophyll-a: SM 10200H
Fecal Coliform: SM 9222D
Enterococci: EnterolertE
RESULTS
The results described in this report represent the physical, biological, and chemical data collected
from all sampling sites on a monthly basis between June 2008 and May 2009. These results are
organized by watershed. All raw data, including parameters not summarized in this section, are
included in Appendix C.
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Rating System
In order to provide a quick-glance assessment of the water quality within a particular sampling
station or watershed, the University of North Carolina at Wilmington (UNCW) has previously
employed a rating system for a number of parameters. This quantitative system assigns a rating
of “GOOD”, “FAIR”, or “POOR” to a sampling station depending on the percentage of samples
exceeding the State standard for dissolved oxygen, turbidity, Chlorophyll-a, Enterococci, and
fecal coliform bacteria. If the recorded value of a parameter exceeds the State standard less than
10% of the times sampled, the station will receive a “Good” rating for the parameter. A “Fair”
rating is assigned when a parameter exceeds the State standard 11-25% of the times sampled.
Parameters measured that exceed the State standard more than 25% of the sampling times are
given a “Poor” rating.
Barnards Creek
The Barnards Creek watershed includes 4,953 acres and is located in the southwestern portion of
the County, just along the City line. The watershed drains portions of Carolina Beach Road at its
headwaters and flows towards River Road before entering into the Cape Fear River. Zoning
within the watershed is comprised of a mix of residential and commercial uses. The land is
classified as a mix of transition, urban, and conservation according to the CAMA land use plan.
This watershed contains approximately 16.9% impervious surface coverage (Hume, 2009).
Sampling was conducted at two sites (BC-CBR and BC-RR) within the Barnards Creek
watershed between the months of June 2008 and September 2009. Between October 2008 and
May 2009, the only site monitored within Barnards Creek was BC-CBR (Figure 2). Due to the
incomplete annual dataset from BC-RR, the data presented below represents the results from BC-
CBR only. However, mean values from individual sites are presented in Tables 6 and 7 and
Figures 3 through 6.
Surface dissolved oxygen within BC-CBR ranged between 5.3 mg/l and 8.6 mg/l with a mean
value of 7.0 mg/l. These values were within an acceptable level above the State standard of 4.0
mg/l for C Sw waters during all sampling events at both the surface and near the bottom of the
water column (Figures 3 and 4).
Chlorophyll-a ranged between 1.0 ug/l and 4.0 ug/l with a mean value of 2.0 ug/l at BC-CBR.
These values did not approach the 40ug/l standard.
Enterococci ranged between 134 CFU/100ml and 2,300 CFU/100ml with a geometric mean
value of 505 CFU/100ml, which is above the NCDENR standard of 500 CFU/100ml for Tier III
waters (Figures 5 and 6).
Nitrate/nitrite levels ranged between 0.01 mg/l and 0.18 mg/l with a mean of 0.09 mg/l.
Orthophosphate levels ranged between 0.01 mg/l and 0.02 mg/l with a mean of 0.01 mg/l.
Turbidity values were generally good ranging between 0 and 19 NTU with a mean value of 4
NTU. No observations exceeded the State standard of 50 NTU for C SW waters.
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Figure 2. Water Quality Sites within the Barnards Creek Watershed
Table 6. Mean values of select parameters from Barnards Creek. Range in parentheses.
Parameter BC-CBR BC-RR
Turbidity (NTU) 4 (0-19) 11 (7-17)1
Dissolved Oxygen (mg/l) 7.0 (5.3-8.6) 5 (4.5-5.4)1
Nitrate/Nitrite (mg/l) 0.09 (0.01-0.18)0.34 (0.21-0.52)1
Orthophosphate (mg/l) 0.01 (0.01-0.02)0.05 (0.01-.08)1
Chlorophyll-a (ug/l) 1.8 (1.0-4.0) 25.0 (10.5-33.4)1
Enterococci (#CFU/100ml)505 (134-2300)2 13 (5-19)1,2
(1)Data from June 2008 through September 2008 only (2)Enterococci values expressed as geometric mean
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Figure 3. Dissolved Oxygen at BC-CBR
Figure 4. Dissolved Oxygen at BC-RR
Figure 5. Enterococci at BC-CBR
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Figure 6. Enterococci at BC-RR
Table 7. Ratings of parameters within sampling stations within Barnards Creek
Parameter BC-CBR BC-RR
Turbidity GOOD GOOD
Dissolved Oxygen GOOD GOOD
Chlorophyll-a GOOD GOOD
Enterococci POOR GOOD
Futch Creek
Futch Creek is located on the New Hanover-Pender County line and drains into the Intracoastal
Waterway. The Futch Creek watershed encompasses approximately 3,136 acres extending from
Scotts Hill Loop Road and Highway 17 on the north and east, to Porters Neck Road on the south.
Zoning within the Futch Creek watershed is predominately residential with a small business
district along Highway 17. The land within the Futch Creek watershed is classified as watershed
resource protection or transition in the CAMA land use plan. This watershed contains
approximately 11.0% impervious surface coverage (Hume, 2009). Sampling was conducted at
five (5) sites (FC-4, FC-6, FC-8, FC-13, and FC-FOY) within the Futch Creek watershed
between the months of June 2008 and September 2008. FC-8 was not sampled between the
months of October 2008 and May 2009 (Figure 7). Due to the incomplete annual dataset from
FC-8, the data discussed below represents the results from FC-4, FC-6, FC-13, and FC-FOY
only. However, mean values from all individual sites are presented in Tables 8 and 9 and
Figures 8 through 17. Due to a technical error associated with the analytical laboratory
contracted to analyze water samples, fecal coliform results were not available from February
2009.
Surface dissolved oxygen within the creek ranged between 4.0 mg/l and 9.7 mg/l with a mean
value of 6.7 mg/l. Along with sporadic low dissolved oxygen levels observed during this study,
four (4) of the five (5) sites contained dissolved oxygen levels below the State standard during
September 2008 (Figures 9 through 13).
Chlorophyll-a ranged between 0.5 ug/l and 10.4 ug/l with a mean value of 3.1 ug/l. None of
these values approached the 40ug/l Chlorophyll-a standard.
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Enterococci ranged between 1 CFU/100ml and 64 CFU/100ml with a geometric mean value of 9
CFU/100ml. No samples within Futch Creek exceeded the NCDENR Enterococci standard of
500 CFU/100ml for Tier III waters.
The geometric mean of fecal coliform in Futch Creek was 11 CFU with a range of 1 to 910
CFUs. This geometric mean was within the NCDENR Shellfish Sanitation single-sample
standard of 14 CFU/100ml. Eight percent (8%) of all samples analyzed for fecal coliform levels
exceeded 43 CFU/100ml. The State standard requires “no more than 10% of samples shall
exceed 43 CFU/100ml)”.
Nitrate/nitrite levels ranged between 0.01 mg/l and 0.06 mg/l with a mean of 0.01 mg/l.
Orthophosphate levels for all samples collected within Futch Creek were 0.01 mg/l.
Turbidity values were generally low ranging between 0 and 18 NTU with a mean value of 2
NTU; no observations exceeded the State standard of 25 NTU for SA waters.
Figure 7. Water Quality Sites within the Futch Creek Watershed
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Table 8. Mean values of select parameters from Futch Creek. Range in parentheses.
Parameter FC-4 FC-6 FC-8 FC-13 FC-FOY
Turbidity
(NTU) 3 (0-16) 1 (0-8) 2 (1-4)1 4 (0-18) 2 (0-14)
Dissolved
Oxygen (mg/l) 6.9 (4.7-9.4) 6.8 (4.8-9.4) 5.3 (4.6-5.9)1 6.6 (4.2-9.7) 6.6 (4.0-9.6)
Nitrate/Nitrite
(mg/l) 0.01 (0.01-0.03) 0.01 (0.01-0.03)0.02 (0.01-0.03)1 0.01 (0.01-0.03) 0.02 (0.01-0.06)
Orthophosphate
(mg/l) 0.01 (0.01-0.01) 0.01 (0.01-0.01)0.01 (0.01-0.01)1 0.01 (0.01-0.01) 0.01 (0.01-0.01)
Chlorophyll-a
(ug/l) 3.0 (1.0-8.1) 3.2 (0.5-8.5) 6.1 (3.4-9.0)1 3.6 (0.5-9.3) 2.8 (1.0-10.4)
Enterococci
(#CFU/100ml) 5 (1-28)2 7 (5-20)2 4 (1-10)1,2 13 (5-64)2 12 (5-64)2
Fecal Coliform
(#CFU/100ml) 4 (1-19)2 6 (1-19)2 10 (4-37)1,2 17 (1-910)2 17 (5-350)2
(1)Data from June 2008 through September 2008 only (2)Enterococci and Fecal Coliform values expressed as geometric mean
Figure 8. Dissolved Oxygen at FC-4
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Figure 9. Dissolved Oxygen at FC-6
Figure 10. Dissolved Oxygen at FC-8
Figure 11. Dissolved Oxygen at FC-13
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Figure 12. Dissolved Oxygen at FC-FOY
Figure 13. Enterococci and Fecal Coliform at FC-4
Figure 14. Enterococci and Fecal Coliform at FC-6
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Figure 15. Enterococci and Fecal Coliform at FC-8
Figure 16. Enterococci and Fecal Coliform at FC-13
Figure 17. Enterococci and Fecal Coliform at FC-FOY
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Table 9. Ratings of parameters within sampling stations within Futch Creek
Parameter FC-4 FC-6 FC-8 FC-13 FC-FOY
Turbidity GOOD GOOD GOOD GOOD GOOD
Dissolved Oxygen GOOD GOOD FAIR FAIR GOOD
Chlorophyll-a GOOD GOOD GOOD GOOD GOOD
Enterococci GOOD GOOD GOOD GOOD GOOD
Fecal Coliform GOOD FAIR FAIR POOR POOR
Lords Creek
The Lords Creek Watershed is located in the southwestern portion of the County and
encompasses approximately 3,047 acres. Zoning within the watershed is completely residential.
This watershed contains approximately 12.6% impervious surface coverage (Hume, 2009).
According to the CAMA land use plan, the land in the watershed is classified as a mix of
conservation, transition, watershed resource protection and a small natural heritage resource
protection designation. Sampling was conducted at one (1) site (LC-RR) within the Lords Creek
watershed (Figure 18). Mean values and ratings from this site are presented in Tables 10 and 11.
Surface dissolved oxygen LC-RR ranged between 4.3 mg/l and 10.8 mg/l with a mean value of
7.3 mg/l. These values were within an acceptable level above the State standard of 4.0 mg/l for
C Sw waters during all sampling events at both the surface and near the bottom of the water
column (Figure 19).
Chlorophyll-a ranged between 3.0 ug/l and 51.8 ug/l with a mean value of 16.5 ug/l. Samples
obtained in June and August exceeded the State standard of 40ug/l for Chlorophyll-a.
Enterococci ranged between 28 CFU/100ml and 631 CFU/100ml with a geometric mean value
of 108 CFU/100ml. Two samples, collected in October 2008 and March 2009, contained high
levels of Enterococci beyond the NCDENR standard of 500 CFU/100ml for Tier III waters
(Figure 20).
Nitrate/nitrite levels ranged between 0.01 mg/l and 0.39 mg/l with a mean of 0.14 mg/l.
Orthophosphate levels ranged between 0.01 mg/l and 0.12 mg/l with a mean of 0.05 mg/l.
Turbidity values were generally moderate ranging between 0 and 38 NTU with a mean value of
11 NTU. No observations exceeded the State standard of 50 NTU for C Sw waters in Lords
Creek during the study period.
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Figure 18. Water Quality Site within the Lords Creek Watershed
Table 10. Mean values of select parameters from Lords Creek. Range in parentheses.
Parameter LC-RR
Turbidity (NTU) 11 (0-38)
Dissolved Oxygen (mg/l) 7.3 (4.3-10.8)
Nitrate/Nitrite (mg/l) 0.14 (0.01-0.39)
Orthophosphate (mg/l) 0.05 (0.01-0.12)
Chlorophyll-a (ug/l) 16.5 (3.0-51.8)
Enterococci (#CFU/100ml)108 (28-631)1
(1)Enterococci values expressed as geometric mean
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Figure 19. Dissolved Oxygen at LC-RR
Figure 20. Enterococci Levels at LC-RR
Table 11. Ratings of parameters within sampling stations within Lords Creek
Parameter LC-RR
Turbidity GOOD
Dissolved Oxygen GOOD
Chlorophyll-a FAIR
Enterococci FAIR
Motts Creek
Motts Creek watershed encompasses approximately 2,389 acres and is located in the
southwestern portion of the County, just below Sanders Road. The Creek drains portions of
Carolina Beach Road at its headwaters and then drains toward River Road before entering into
the Cape Fear River. Zoning in the watershed is predominately residential with commercial
business districts along Carolina Beach Road. Land in the watershed is classified as transition,
conservation or wetland resource protection according to the CAMA land use plan. This
watershed contains approximately 12.6% impervious surface coverage (Hume, 2009). Sampling
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was conducted at three (3) sites (MOT-CBR, MOT-ND, MOT-RR) within the Motts Creek
watershed between the months of June 2008 and September 2008 (Figure 21). Due to budgetary
constraints, MOT-RR was not monitored between October 2008 and May 2009. The results
discussed below only include the data collected from MOT-CBR and MOT-ND. The results
from all three individual stations are presented in Figures 22 through 27 and Tables 12 and 13.
Surface dissolved oxygen within Motts Creek ranged between 3.8 mg/l and 9.2 mg/l with a mean
value of 6.8 mg/l (Figures 22 through 24).
Chlorophyll-a ranged between 1.0 ug/l and 10.0 ug/l with a mean value of 2.8 ug/l. These values
did not approach the 40ug/l standard.
Enterococci ranged between 128 CFU/100ml and 2,800 CFU/100ml with a geometric mean
value of 586 CFU/100ml. MOT-ND and MOT-CBR each exceeded the NCDENR standard of
500 CFU/100ml for Tier III waters during five (5) and eight (8) of the twelve (12) times they
were samples, respectively (Figures 25 through 27).
Fecal coliform samples were collected during April 2008 sampling from MOT-ND and MOT-
CBR. Neither sample exceeded the NCDWQ single-sample standard of 400 CFU/100ml.
Nitrate/nitrite levels ranged between 0.01 mg/l and 0.29 mg/l with a mean of 0.10 mg/l.
Orthophosphate levels ranged between 0.01 mg/l and 0.05 mg/l with a mean of 0.02 mg/l.
Turbidity values were generally good ranging between 0 and 27 NTU with a mean value of 8
NTU. No turbidity observations exceeded the State standard of 50 NTU for C Sw waters.
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Figure 21. Water Quality Sites within the Motts Creek Watershed
Table 12. Mean values of select parameters from Motts Creek. Range in parentheses.
Parameter MOT-CBR MOT-ND MOT-RR
Turbidity (NTU) 9 (0-33) 7 (0-27) 8 (5-9)
Dissolved Oxygen (mg/l) 7.0 (3.8-9.2) 6.6 (4.4-8.2) 4.4 (3.3-6.1)
Nitrate/Nitrite (mg/l) 0.09(0.01-0.19) 0.11 (0.01-0.29)0.21 (0.04-0.46)
Orthophosphate (mg/l) 0.01 (0.01-0.04) 0.02 (0.01-0.05)0.03 (0.01-0.04)
Chlorophyll-a (ug/l) 2.1 (1.0-4.0) 3.6 (1.0-10.0) 3.6 (1.0-10.0)
Enterococci (#CFU/100ml) 464 (128-2800)1 708 (201-2600)1 33 (1-908)1
(1)Enterococci values expressed as geometric mean
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Figure 22. Dissolved Oxygen at MOT-CBR
Figure 23. Dissolved Oxygen at MOT-ND
Figure 24. Dissolved Oxygen at MOT-RR
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Figure 25. Enterococci and Fecal Coliform at MOT-CBR
Figure 26. Enterococci and Fecal Coliform at MOT-ND
Figure 27. Enterococci at MOT-RR
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Table 13. Ratings of parameters within sampling stations within Motts Creek
Parameter MOT-CBR MOT-ND MOT-RR
Turbidity GOOD GOOD GOOD
Dissolved Oxygen GOOD GOOD POOR
Chlorophyll-a GOOD GOOD FAIR
Enterococci POOR POOR FAIR
Pages Creek
Located in northeastern New Hanover County and encompassing 2,044 acres, Pages Creek
watershed drains into the Intracoastal Waterway, north of Middle Sound Loop Road. Zoning
within the Pages Creek watershed is predominately residential, with commercial zoning along
Highway 17. The land within the Pages Creek watershed is predominately classified as
watershed resource protection and conservation, with a small portion classified as transitional
according to the CAMA land use plan. This watershed contains approximately 23.2%
impervious surface coverage (Hume, 2009). Sampling was conducted at three (3) sites (PC-
BDDS, PC-BDUS, and PC-M) within the Motts Creek watershed (Figure 28). Mean values and
ratings from all individual sites are presented in Tables 14 and 15.
Surface dissolved oxygen within Pages Creek ranged between 3.2 mg/l and 9.7 mg/l with a mean
value of 6.2 mg/l. While dissolved oxygen at PC-M was acceptable during all sampling events,
the dissolved oxygen within PC-BDDS and PC-BDUS were lower than the State standard of 5.0
mg/l for SA waters on numerous occasions (Figures 29 through 31).
Chlorophyll-a ranged between 3.1 ug/l and 55.0 ug/l with a mean value of 9.8 ug/l. One sample,
taken from PC-BDDS and one sample taken from PC-BDUS, exceeded the State standard of 40
ug/l for Chlorophyll-a.
Enterococci ranged between 9 CFU/100ml and 60,000 CFU/100ml with a geometric mean value
of 134 CFU/100ml. While samples collected from PC-M did not contain high levels of
Enterococci, six (6) and three (3) samples from PC-BDDS and PC-BDUS, respectively,
contained levels higher than the NCDENR standard of 500 CFU/100ml.
Fecal coliform levels ranged between 5 CFU/100ml and 11,000 CFU/100ml with a geometric
mean of 100 CFU/100ml. Fecal coliform levels exceeded the NCDENR Shellfish Sanitation
single-sample standard of 14 CFU/100ml on eight (8) and eleven (11) of the eleven (11)
sampling event at PC-BDDS and PC-BDUS. This standard was breached at PC-M on two
occasions (Figures 32 through 34). Sixty-four percent (64%) of all samples analyzed for fecal
coliform levels exceeded 43 CFU/100ml. The State standard allows “no more than 10% of
samples shall exceed 43 CFU/100ml”.
Nitrate/nitrite levels ranged between 0.01 mg/l and 0.03 mg/l with a mean of 0.01 mg/l.
Orthophosphate levels ranged between 0.01 mg/l and 0.07 mg/l with a mean of 0.02 mg/l.
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Turbidity values were generally good ranging between 0 and 35 NTU with a mean value of 6
NTU. Two observed turbidity values exceeded the State standard of 25 NTU for class SA
waters.
Figure 28. Water Quality Sites within the Pages Creek Watershed
Table 14. Mean values of select parameters from Pages Creek. Range in parentheses.
Parameter PC-BDUS PC-BDDS PC-M
Turbidity (NTU) 7 (0-35) 8 (8-32) 3 (0-10)
Dissolved Oxygen (mg/l) 6.2 (3.8-9.1) 5.5 (3.2-8.5) 6.8 (5.4-9.7)
Nitrate/Nitrite (mg/l) 0.01 (0.01-0.03) 0.01 (0.01-0.03) 0.01 (0.01-0.03)
Orthophosphate (mg/l) 0.02 (0.01-0.03) 0.03 (0.01-0.06) 0.01 (0.01-0.01)
Chlorophyll-a (ug/l) 11.5 (2.0-48.0) 14.9 (1.0-55.0) 3.1 (1.0-7.3)
Enterococci (#CFU/100ml) 187 (15-819)1 205 (30-60,000)1 9 (5-55)1
Fecal Coliform (#CFU/100ml) 85 (5-905)1 209 (28-11,000)1 8 (5-19)1
(1)Enterococci and Fecal Coliform values expressed as geometric mean
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Figure 29. Dissolved Oxygen at PC-BDDS
Figure 30. Dissolved Oxygen at PC-BDUS
Figure 31. Dissolved Oxygen at PC-M
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Figure 32. Enterococci and Fecal Coliform at PC-BDDS
Figure 33. Enterococci and Fecal Coliform at PC-BDUS
Figure 34. Enterococci and Fecal Coliform at PC-M
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Table 15. Ratings of parameters within sampling stations within Pages Creek
Parameter PC-BDDS PC-BDDS PC-M
Turbidity GOOD GOOD GOOD
Dissolved Oxygen POOR POOR GOOD
Chlorophyll-a GOOD GOOD GOOD
Enterococci POOR POOR FAIR
Fecal Coliform POOR POOR FAIR
Prince Georges
Prince Georges Creek drains into the Cape Fear River. The Prince Georges Creek watershed is
approximately 14,589 acres and drains most of Castle Hayne, extending eastward across I-40
into the Blue Clay Road area. Zoning within the Prince Georges Creek watershed is
predominately residential with some business and light industrial districts within Castle Hayne.
Most of the land within the Prince Georges Creek watershed is classified as aquifer resource
protection, conservation or transition according to the CAMA land use plan. This watershed
contains approximately 10.1% impervious surface coverage (Hume, 2009). Sampling was
conducted at three (3) sites (PG-CH, PG-ML, and PG-NC) within the Prince Georges Creek
watershed (Figure 35). Mean values and ratings from all individual sites are presented in Tables
16 and 17.
Surface dissolved oxygen within Prince Georges Creek ranged between 0.1 mg/l and 9.1 mg/l
with a mean value of 4.4 mg/l. While these values were within the acceptable range above the
State standard of 4.0 mg/l for C Sw at PG-CH and PG-ML, surface dissolved oxygen values at
PG-NC and PG-CH were below this standard during eight (8) and six (6) sampling events,
respectively (Figures 36 through 38).
Chlorophyll-a ranged between 0.5 ug/l and 28.2 ug/l with a mean value of 5.5 ug/l. These values
did not exceed the 40ug/l standard.
Enterococci ranged between 10 CFU/100ml and 3,000 CFU/100ml with a geometric mean value
of 185 CFU/100ml. During this study, three (3) and four (4) samples from PG-CH and PG-ML,
respectively, contained Enterococci levels above the NCDENR standard of 500 CFU/100ml for
Tier III waters. One (1) sample from PG-NC exceeded this value during the same time period
(Figures 39 through 41).
Fecal coliform samples were collected during April 2008 sampling from each monitoring site
within Prince Georges Creek. No samples exceeded the NCDWQ single-sample standard of 400
CFU/100ml.
Nitrate/nitrite levels ranged between 0.01 mg/l and 0.36 mg/l with a mean of 0.04 mg/l.
Orthophosphate levels ranged between 0.01 mg/l and 0.09 mg/l with a mean of 0.03 mg/l.
Turbidity values were generally good ranging between 0 and 15 NTU with a mean value of 3
NTU. No observed turbidity values exceeded the State standard of 50 NTU for C Sw waters.
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Figure 35. Water Quality Sites within the Prince Georges Creek Watershed
Table 16. Mean values of select parameters from Prince Georges Creek. Range in
parentheses.
Parameter PG-CH PG-ML PG-NC
Turbidity (NTU) 3 (0-15) 2 (0-12) 3 (0-10)
Dissolved Oxygen (mg/l) 4.4 (1.0-7.5) 5.8 (3.1-9.1) 3.0 (0.1-8.9)
Nitrate/Nitrite (mg/l) 0.03 (0.01-0.10)0.07 (0.01-0.36)0.03 (0.01-0.07)
Orthophosphate (mg/l) 0.04 (0.01-0.07)0.03 (0.01-0.06)0.02 (0.01-0.09)
Chlorophyll-a (ug/l) 5.3 (0.5-28.2) 7.0 (0.5-26.0) 4.2 (1.0-13.4)
Enterococci (#CFU/100ml) 185 (10-1,546)1 331 (10-3,000)1 39 (2-2,000)1
(1)Enterococci values expressed as geometric mean
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Figure 36. Dissolved Oxygen at PG-CH
Figure 37. Dissolved Oxygen at PG-ML
Figure 38. Dissolved Oxygen at PG-NC
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Figure 39. Enterococci and Fecal Coliform at PG-CH
Figure 40. Enterococci and Fecal Coliform at PG-ML
Figure 41. Enterococci and Fecal Coliform at PG-NC
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Table 17. Ratings of parameters within sampling stations within Prince Georges Creek
Parameter PG-CH PG-ML PG-NC
Turbidity GOOD GOOD GOOD
Dissolved Oxygen POOR FAIR POOR
Chlorophyll-a GOOD GOOD GOOD
Enterococci FAIR POOR GOOD
Smith Creek
Located in north-central New Hanover County and containing approximately 14,665 acres, the
Smith Creek watershed drains into the lower northeast Cape Fear River, just north of the Isabelle
Holmes Bridge. The watershed drains land within the City limits and the unincorporated
County, including the Wilmington International Airport. Zoning within the Smith Creek
watershed is a mix of industrial, residential, and commercial. The land within the watershed is
predominately classified as urban and transition, with a small portion classified as conservation.
This watershed contains approximately 21.9% impervious surface coverage (Hume, 2009).
Along with increased development and impervious surfaces, water quality in Smith Creek has
declined in recent years. High bacteria levels have been reported, as well as low dissolved
oxygen levels. As a result, Smith Creek has been listed on the 303(d) list for impaired waters
due to impaired biological integrity. Sampling was conducted at five (5) sites (SC-CH, SC-23,
SC-NK, SC-GR, SC-CD) within the Smith Creek watershed (Figure 42). Mean values and
ratings from all individual sites are presented in Tables 18 and 19.
Surface dissolved oxygen within the creek ranged between 3.3 mg/l and 10.9 mg/l with a mean
value of 6.5 mg/l. With the exception of one observation from SC-CH and SC-23 during August
2008, these values were within an acceptable level above the State standard of 4.0 mg/l for C Sw
waters (Figures 43 through 47).
Chlorophyll-a ranged between 1.0 ug/l and 46.0 ug/l with a mean value of 8.0 ug/l. One sample
collected from SC-NK exceeded the 40ug/l standard in May 2009. All other samples were
within the acceptable range.
Enterococci ranged between 5 CFU/100ml and 21,000 CFU/100ml with a geometric mean value
of 496 CFU/100ml. A number of samples exceeded the NCDENR standard of 500 CFU/100ml
for Tier III waters including two (2) from SC-23, ten (10) from SC-CD, two (2) samples from
SC-NK, one (1) from SC-CH, and seven (7) from SC-GR exceeded the NCDENR standard of
276 CFU/100ml for Tier waters (Figures 48 through 52).
Nitrate/nitrite levels ranged between 0.01 mg/l and 0.53 mg/l with a mean of 0.12 mg/l.
Orthophosphate levels ranged between 0.01 mg/l and 0.11 mg/l with a mean of 0.04 mg/l.
Turbidity values were generally good ranging between 0 and 45 NTU with a mean value of 8
NTU. No observed turbidity values exceeded the State standard of 50 NTU for SW class C
waters.
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COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
Figure 42. Water Quality Sites within the Smith Creek Watershed
Table 18. Mean values of select parameters from Smith Creek. Range in parentheses.
Parameter SC-23 SC-CD SC-CH SC-GR SC-NK
Turbidity
(NTU) 11 (4.0-20.0) 4 (0.0-12.0) 17 (4.0-45.0) 2 (0.0-8.0) 4 (0.0-15.0)
Dissolved
Oxygen (mg/l) 7.0 (3.5-10.5) 8.5 (6.7-9.7) 7.3 (3.3-10.9) 8.2 (6.3-10.6) 6.5 (4.4-9.7)
Nitrate/Nitrite
(mg/l) 0.15 (0.00-0.30) 0.06 (0.01-0.13) 0.25 (0.01-0.53)0.08 (0.01-0.20) 0.07 (0.01-.015)
Orthophosphate
(mg/l) 0.05 (0.01-0.09) 0.02 (0.01-0.05) 0.06 (0.03-0.11)0.02 (0.01-0.06) 0.03 (0.01-0.10)
Chlorophyll-a
(ug/l) 9.8 (2.0-24.8) 3.1 (1.0-7.0) 10.0 (1.0-36.0) 2.5 (1.0-7.0) 14.9 (2.0-46.0)
Enterococci
(#CFU/100ml) 84 (5-637)1 1,418 (109-21,000)1 49 (10-819)1 753 (96-6,000)1 175 (41-2,000)1
(1)Enterococci values expressed as geometric mean
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COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
Figure 43. Dissolved Oxygen at SC-23
Figure 44. Dissolved Oxygen at SC-CD
Figure 45. Dissolved Oxygen at SC-CH
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COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
Figure 46. Dissolved Oxygen at SC-GR
Figure 47. Dissolved Oxygen at SC-NK
Figure 48. Enterococci at SC-23
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COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
Figure 49. Enterococci at SC-CD
Figure 50. Enterococci at SC-CH
Figure 51. Enterococci at SC-GR
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COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
Figure 52. Enterococci at SC-NK
Table 19. Ratings of parameters within sampling stations within Smith Creek
Parameter SC-23 SC-CD SC-CH SC-GR SC-NK
Turbidity GOOD GOOD GOOD GOOD GOOD
Dissolved Oxygen GOOD GOOD GOOD GOOD GOOD
Chlorophyll-a GOOD GOOD GOOD GOOD GOOD
Enterococci FAIR POOR GOOD POOR FAIR
Comprehensive Rating by Watershed
When combining all results from each site within individual watersheds, it is possible to obtain a
“snapshot” of water quality within each watershed (Table 20). Barnards Creek demonstrates
“good” water quality with the exception of Enterococci, which was in the “poor” category.
Futch Creek has also shown to contain good ratings; however dissolved oxygen was shown to be
“fair” while fecal coliform was determined to be “poor”. Lords Creek was “good” for turbidity
and dissolved oxygen and “fair” for Chlorophyll-a and Enterococci. Motts Creek contained
“good” turbidity and Chlorophyll-a,“fair” dissolved oxygen, and “poor” Enterococci. Pages
Creek also demonstrated “good” ratings for turbidity and dissolved oxygen. Dissolved oxygen
and fecal coliform were “poor” and Enterococci was “fair”. Similar to Pages Creek, Prince
Georges Creek had “good” ratings for turbidity and dissolved oxygen, “poor” rating for
dissolved oxygen, and “fair” rating for Enterococci. Smith Creek had “good” water quality for
all parameters with the exception of Enterococci, which was rated as “poor”.
Table 20. Ratings of parameters within each watershed
Parameter Barnards
Creek
Futch
Creek
Lords
Creek
Motts
Creek
Pages
Creek
Prince
Georges
Creek
Smith
Creek
Turbidity GOOD GOOD GOOD GOOD GOOD GOOD GOOD
Dissolved Oxygen GOOD FAIR GOOD FAIR POOR POOR GOOD
Chlorophyll-a GOOD GOOD FAIR GOOD GOOD GOOD GOOD
Enterococci POOR GOOD FAIR POOR FAIR FAIR POOR
Fecal Coliform N/A POOR N/A N/A POOR N/A N/A
39
COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
Source Tracking
As a supplement to the regular monthly water quality monitoring, a separate sampling effort was
undertaken to determine the source of bacterial contamination within Pages Creek. As reported
above, two of the three sampling sites within Pages Creek (PC-BDDS and PC-BDUS) contain
high levels of Enterococci and fecal coliform bacteria on a frequent basis. Although these fecal
indicator bacteria are typically not pathogenic themselves, they correlate well with levels of
illness in swimmers, in particular Enterococci (US EPA 1986). Sanitary sewage, since it carries
human waste, can be a source of intestinal pathogens which can cause disease. Research,
however, has shown that non-sewage sources of indicator microbes are also found in the
environment, with extensive documentation that soils and beach sands serve as important
reservoirs for indicators (Fujioka, et al., 1999). In some cases, the fine sediments and underlying
sediments in recreational beach areas have been implicated as a source of Enterococci (Indest,
2003). High levels of impervious surface coverage often facilitates increased amounts of
stormwater runoff (potentially containing pollutants, soils, and associated bacteria) into nearby
water bodies. Furthermore, domesticated animals (dogs and cats) along with wildlife such as
deer, raccoons, and birds are known to live and defecate within the Pages Creek watershed.
With this in mind, New Hanover County officials funded a source tracking project to determine
the origin of bacterial contamination within two water quality monitoring stations within Pages
Creek in proximity to Bayshore Drive where high levels of bacteria have been documented.
Four sampling events were conducted through the course of this study; two (2) during dry
periods and two (2) during rain events. Results demonstrate that the bacterial levels
(Enterococcus and fecal coliform) within water samples collected from PC-BDDS and PC-
BDUS were excessive following all fours sampling events. Genetic analysis of samples
collected from both sites indicated the presence of human fecal bacteria within these locations in
Pages Creek. Other sources of contamination were shown to be derived from ruminants such as
deer. Furthermore, the presence of optical brighteners, a chemical compound often found in
laundry detergents, indicated that either sewage or septic system leachate was polluting the creek
waters. In conclusion, the results of this project suggest that a portion of the bacterial load
entering Pages Creek during this study originated from human sources. There is a strong
likelihood that failing sewer or septic tank infrastructure within the area may be contributing to
the problem. See Appendix C for the complete Source Tracking Report.
Rainfall and Enterococci Levels
Along with potential input via failing septic and sewer infrastructure, it is a common belief that a
direct pathway of bacterial contamination into waterways is via stormwater runoff following rain
events. Young and Thackston (1999) noted a positive correlation between fecal coliform counts
and high levels of rainfall. They further noted that the high bacteria counts were likely due to
stormwater runoff. The relative high levels of impervious surface coverage within several of the
watersheds investigated in this study would suggest that a rain event may produce excessive
stormwater runoff, thereby influencing the amount of Enterococci entering the watersheds.
During the course of this study, 301 samples were collected during a dry period while 93
samples were collected within 24-hours of a rain event. The highest individual Enterococci
count (60,000 CFU) was obtained at PC-BDUS immediately following a heavy rainfall. Large
amounts of runoff were observed flowing down the boat ramp located in proximity of the
monitoring site during sampling. To test if the probability of Enterococci levels exceeding local
minimum thresh-holds (275 or 500 CFU) was influenced by rain events a logistic regression was
40
COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
performed. Sample event (time) was generally specified and a dichotomous variable was added
that indicated if a sample was collected within 24 hours of a rain event. Across monitoring
events, sites sampled within 24 hours of a rain event did not exhibit an increased probability of
Enterococci levels exceeding maximum thresh-holds (Wald Chi-Sq. = 2.54, p = 0.111).
DISCUSSION
Water quality is an important issue in the region due to the fact that there are many economic and
recreational opportunities that are supported by the aquatic resources in and around these
waterways. One of the greatest threats to water quality in this area is stormwater runoff created
by increased impervious surface coverage (Mallin et al., 2000). Polluted stormwater runoff can
have many adverse effects on plants, fish, animals and people. Excess nutrients can cause algae
blooms while bacteria and other pathogens can wash into swimming areas and create health
hazards. New Hanover County has experienced rapid growth and development over the past
several decades. In 1990, the population within the County was 120,284. By 2006, the
population grew over 50% to 182,591 (U.S. Census Bureau, 2006). Along with this population
increase and subsequent stormwater runoff, numerous septic tanks, aging wastewater
infrastructure, and other factors potentially impact the water quality within the County’s creeks.
With this in mind, it is important to monitor the water quality of these local systems to determine
potential impacts to both human health and ecosystem function.
The results of this water quality assessment describe high variability within a number of
parameters examined in this study. To fully understand the seasonal effects on water quality, it
is important to conduct sampling throughout the entire year. Therefore, the summarized results
from each watershed only incorporate the data obtained from sampling sites monitored over the
course of the entire twelve (12) month reporting period.
Typically, water quality degrades as the water warms and oxygen is not as readily dissolved in
the water column. Furthermore, longer days allow for increased photosynthetic activity allowing
for an increase in phytoplankton blooms. While often more problematic in the summer months,
algal blooms are less common in the fall and winter when water temperature decreases. High
levels of chlorophyll-a and nutrients along with increases in pH and turbidity may indicate the
presence of an algal bloom. Throughout the course of this study, pH values were found to be
within acceptable ranges (5.9-9.0) as were turbidity values (0 to 45 NTU). The lack of increased
pH and turbidity along with generally low chlorophyll-a levels indicate that algal blooms were
generally not a problem. However, as the water within these creeks warmed significantly,
chlorophyll-a concentrations increased compared to previous months, particularly within Motts
Creek, Pages Creek, and Lords Creek. Six water samples collected within these watersheds
contained chlorophyll-a concentration exceeding the State standard. These were collected in
June and August of 2008 as the water temperature increased.
The chemical parameter nitrate/nitrite showed a marked difference between the tidal creeks
located in proximity to the Intracoastal Waterway and the creeks flowing into the Cape Fear
River. The nitrate/nitrite levels were approximately an order of magnitude lower in Pages Creek
and Futch Creek, the two creeks draining into the ICW. Further study is required to determine
the cause of this sharp difference in nitrate/nitrite levels within these creeks.
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COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
Dissolved oxygen levels at a number of sites were below the State standard of 5.0 ml/l in SA
waters and 4.0 mg/l in C Sw waters. Two sites within Pages Creek, PC-BDDS and PC-BDUS,
experienced low dissolved oxygen during four (4) and five (5) sampling events, respectively. All
five sites in Futch Creek experienced low dissolved oxygen during September when the water
was the warmest. FC-13, located in closest proximity to the headwaters, contained low dissolved
oxygen on three (3) of the twelve monitoring events. Of the creeks draining into the Cape Fear
River, Prince Georges Creek demonstrated the lowest dissolved oxygen due to the physical
setting surrounding the creek. PG-NC demonstrated low dissolved oxygen eight (8) times of the
twelve (12) times sampled. This portion of the creek is characterized by a broad shallow bank in
a swamp-like setting. It is typical of swamps to contain low levels of dissolved oxygen and
higher levels of pH, as observed. Therefore, the low dissolved oxygen observed in Prince
Georges Creek, particularly at PG-NC could be regarded as a natural phenomenon. Other low
dissolved oxygen levels were observed at MOT-CBR, MOT-RR, SC-23, and SC-CH. These low
values were obtained during June, July, and August of 2008 when water temperatures were
elevated its capacity to contain dissolved oxygen was diminished.
High levels of Enterococci bacteria persisted within all watersheds throughout the study period,
with the exception of Futch Creek. Specifically, Enterococci levels exceeded the State standard
in individual sampling sites within Prince Georges Creek, Smith Creek, Pages Creek, Barnards
Creek, Lords Creek, and Motts Creek 22%, 37%, 25%, 44%, 17%, and 50% of the time,
respectively. Along with Enterococci, fecal coliform bacteria was tested within Pages Creek and
Futch Creek. A very high percentage of samples exceeded the single-sample NCDENR Shellfish
Sanitation standard of 14 CFU/100ml within these creeks. In fact, 31% of all samples collected
within Futch Creek exceeded this standard. Sixty-four percent (64%) of all samples collected
within Pages Creek also exceeded this standard.
Sources of nutrient and fecal bacteria pollutants can include fertilizers, septic system leachate,
leaking sewer mains, wild and domestic animal wastes, and overland runoff (Spivey, 2008). In
order to understand and manage fecal bacteria pollution in any body of water, one must first be
able to identify the source of the pollution (Kelsey et al. 2004). Previous studies have concluded
that increasing the amount of impervious surface coverage increases runoff, stream flow, and the
amount of pollutants reaching surface waters (Griffin et al, 1990; Schueler, 1994, Mallin, 2001).
Mallin et al. (2000) determined a strong correlation between impervious surface coverage and
fecal coliform bacteria levels in New Hanover County. Higher impervious surface coverage was
found to correlate with a higher geometric mean of fecal coliform bacteria within individual
watersheds. New Hanover County has experienced high rates of growth over the past several
decades. Along with population increases, the associated development of buildings, roadways,
and parking lots within the county has created increased areas of impervious surface coverage.
These pollutants include hydrocarbons, bacteria, and nutrients including nitrogen. Major sources
of anthropogenic nitrogen are fertilizer application, wastewater disposal and atmospheric
deposition (Howarth and Marino, 2006). The conversion of natural landscapes to impervious
surfaces removes the natural filtration capacity of the land, thereby facilitating increased
concentration of pollutants migrating directly into waterways.
A recent assessment of the impervious surface coverage within the watersheds of New Hanover
County was performed (Hume, 2008). Impervious surface percentages were determined to be
42
COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
10.1% in Prince Georges Creek watershed, 11.0% in Futch Creek watershed, 12.6% in Lords
Creek watershed, in 13.5% Motts Creek watershed, in 16.9% Barnards Creek watershed, 21.9%
in Smith Creek watershed, and 23.3% in Pages Creek watershed (Figure 53).
Figure 53. Percent of impervious surface coverage within New Hanover County
watersheds
While the results presented in this report do not suggest that rainfall significantly influences the
amount of Enterococci in the water column, it should be noted that the highest levels of
Enterococci (60,000 CFU) were obtained at PC-BDUD shortly after a heavy rain event. This
analysis was conducted with a limited sample size, and while significant results were found, a
larger sampling size would be recommended. To bolster this claim, stormwater runoff was
observed flowing down the boat ramp at PC-BDUS directly into the sampling site, thereby
confirming that stormwater runoff could have contributed to the extremely high Enterococci
level. In general, the high levels of bacteria within the tidal creeks of New Hanover County
suggest that stormwater runoff may provide a significant source of contamination.
The other potential source of contamination could originate from failing sewage and septic
systems. A recent source tracking study found bacteria originating from humans, ruminants, and
canines within six (6) tidal creeks in New Hanover County (Spivey, 2008). The results of the
source tracking effort included in this report indicate similar results. The source of the human-
borne bacteria is indicative of either sewer-line problems, septic system failures, or a general
persistence in the bacteria itself (Spivey, 2008).
In order to reduce the amount of harmful pollutants and pathogens in the tidal creeks within New
Hanover County, we recommend two courses of action. First, knowing that stormwater runoff is
43
COASTAL PLANNING & ENGINEERING OF NORTH CAROLINA, INC.
one source of contamination, it is suggested that the County investigates advanced stormwater
management practices including the development of constructed wetlands, grassy swales, and
other load reducing best management practices. Second, the wastewater infrastructure (septic
and sewer) should be fully assessed in an attempt to identify chronic leaks. New Hanover
County and the Cape Fear Public Utility Authority have begun to investigate the presence of
abandoned septic tanks and malfunctioning sewage lift stations in proximity to Pages Creek.
These efforts should continue and be extended to the other watersheds experiencing high levels
of bacterial contamination as indicated in this study.
LITERATURE CITED
del Mar Lleò, M.; Bonato, B.; Benedetti, D.; and Canepari, P., 2005. Survival of enterococcal
species in aquatic environments. FEMS Microbiology Ecology, 5 (4):189-196.
Fujioka et al., 1999 R.S. Fujioka, C. Sian-Denton, M. Borja, J. Castro and K. Morphew, Soil: the
environmental source of Escherichia coli and enterococci in Guam’s stream, Journal of Applied
Microbiology. 85: 83S–89S
Graczyk et al., 2007 T.K. Graczyk, D. Sunderland, L. Tamang, T.M. Shields, F.E. Lucy and P.N.
Breysse, Quantitative evaluation of the impact of bather density on levels of human-virulent
microspordian spores in recreational waters, Applied Environmental Microbiology. 73: 4095–
4099.
Griffin, D.M., Jr., Grizzard, T.J., Randall, C.W., Helsel, D.R., and Hartigan, J.P. 1980. Analysis
of non-point pollution export from small catchments. Journal of Water Pollution Control
Federation, 52: 780-790.
Hanes, N.B.; and Frangela, R., 1967. Effect of seawater concentration on survival of indicator
bacteria. Journal of the Water Pollution Control Federation 39:97-104.
Harrington R.N. and Cahoon, L.B., 2007. Fecal indicator bacteria in the water and sediments of
local boat ramps. pp. 68-80, within Environmental Quality of Wilmington and New Hanover
County Watersheds 2005-2006, CMS Report 07-01, UNCW Center for Marine Science
Research.
Howarth, R.W. and Marino, R. 2006. Nitrogen as the limiting nutrient for eutrophication in
coastal marine ecosystems: Evolving views over three decades. Limnology and Oceanography,
51: 364-376.
Hume, A. 2008. Determination of Impervious Surface in New Hanover County, North Carolina.
Report submitted to New Hanover County. Wilmington, North Carolina.
Indest, 2003 Indest, K., 2003. Interim guidance on assessing the risk posed by pathogens
associated with dredged material (No. ERDC/TN EEDP-01-49).
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45
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Jeng, J.G., Bradford, H, and Englande, A.J. 2004. "Comparison of E. coli, enterococci, and fecal
coliform as indicators for brackish water quality assessment". Water Environmental Research.
76: 245–55.
Kelsey, H., Porter, D.E, Scott, G., Neet, M., and White, D. 2004. Using geographic information
systems and regression analysis to evaluate relationships between land use and fecal coliform
bacterial pollution. Journal of Experimental Marine Biology and Ecology. 298:197-209.
Kwak, T.J. and Zedler, J.B. 1997. Food web analysis of southern California coastal wetlands
using multiple stable isotopes. Oecologia 110: 262–277.
Mallin, M.A.; Williams, K.E.; Esham, C.E.; and Lowe, P.R., 2000. Effect of human
development on bacteriological water quality in coastal watersheds. Ecological Applications
10:1047-1056.
Mallin, M.A., Ensign, S.H., McIver, M.R., Shank, G.C., and Fowler, P.K. 2001. Demographic,
landscape, and meteorological factors controlling the microbial pollution of coastal waters.
Hydrobiologia. 460: 185-193.
Mallin, M.A., 2008. University of North Carolina at Wilmington, Aquatic Ecologist. Personal
communication regarding historical dissolved oxygen data from Futch Creek and Pages Creek.
Odum, W.E., Smith, T.J., Hoover, J.K., and McIvor, C.C. 1984. The Ecology of Tidal
Freshwater Marshes of the United States East Coast: A Community Profile. , U.S. Fish and
Wildlife Service FWS/OBS-83/17, 177 pp.
Schueler, T., 1994. The importance of imperviousness. Water Protection Technology. 1: 100-
111.
U.S. Census Bureau, 2006 Population Estimates, Census 2000, 1990 Census
U.S. Environmental Protection Agency. 1984. Health effects criteria for fresh recreational
waters. EPA-600/1-84-004, U.S. Environmental Protection Agency, Washington, D.C.
U.S. Environmental Protection Agency. 1986. Ambient Water Quality Criteria for Bacteria-
1986. EPA-440/5/84-002, U.S. Environmental Protection Agency, Washington, D.C.
Young, K.D. and Thackston, E.L. 1999. Housing density and bacterial loading in urban streams.
Journal of Environmental Engineering. 125:1177-1180.
APPENDIX A
Photographs of Sampling Sites
Barnards Creek at Carolina Beach Road (BC-CBR)
Barnards Creek at River Road (BC-RR)
Futch Creek 4 (FC-4)
Futch Creek 6 (FC-6)
Futch Creek 8 (FC-8)
Futch Creek 13 (FC-13)
Futch Creek at Foy Branch (FC-FOY)
Lords Creek at River Road (LC-RR)
Motts Creek at Carolina Beach Road (MOTT-CBR)
Motts Creek at Normandy Drive (MOT-ND)
Motts Creek at River Road (MOT-RR)
Pages Creek at Bayshore Drive Upstream (PC-BDUS)
Pages Creek at Bayshore Drive (PC-BDDS)
Pages Creek Mouth (PC-M)
Prince Georges Creek at Castle Hayne Road (PG-CH)
Prince Georges Creek at Marathon Landing (PG-ML)
Prince Georges Creek at North College Road (PG-NC)
Smith Creek at Candlewood Drive (SC-CD)
Smith Creek at Castle Hayne Road (SC-CH)
Smith Creek at 23rd Street (SC-23)
Smith Creek at North Kerr Ave. (SC-NK)
Smith Creek at Gordon Road (SC-GR)
APPENDIX B
Raw Data
Da
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7
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7
.
2
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6
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8
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N
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7
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7
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.
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9
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7
.
2
1
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N
/
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7
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7
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7
2
5
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9
1
4
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7
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4
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7
.
1
5
N
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7
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7
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8
7
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4
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7
8
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7
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9
7
N
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7
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7
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9
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7
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8
5
N
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7
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6
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7
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6
9
N
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7
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7
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5
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8
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7
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6
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6
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5
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7
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9
3
N
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4
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7
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7
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6
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1
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6
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3
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1
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6
6
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7
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5
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7
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6
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3
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6
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8
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4
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7
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4
7
N
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7
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7
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5
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7
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7
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7
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N
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6
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8
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6
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6
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7
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7
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7
0
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1
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3
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6
.
6
7
N
/
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5
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1
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6
.
5
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.
8
5
2
%
7
.
2
8
6
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7
N
/
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1
9
.
4
0
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8
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1
4
9
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4
7
.
7
3
.
5
4
9
%
7
.
1
1
5
N
/
A
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/
A
N
/
A
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/
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/
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1
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3
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1
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7
8
7
%
7
.
2
0
1
0
9
N
/
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7
.
0
0
.
1
3
0
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0
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1
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9
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5
9
6
4
1
4
.
0
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.
5
5
1
%
7
.
2
1
4
3
7
1
6
.
5
1
6
.
5
0
.
4
0
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2
6
.
2
2
4
9
0
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1
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0
1
1
%
6
.
9
1
6
N
/
A
N
/
A
N
/
A
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/
A
N
/
A
8/
5
/
0
8
0
.
0
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C
-
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H
2
.
1
3
0
.
8
2
5
9
3
8
1
4
.
0
3
.
3
4
8
%
7
.
1
2
8
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
8/
5
/
0
8
0
.
0
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C
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R
0
.
1
2
6
.
4
2
1
0
0
.
1
6
.
3
7
8
%
7
.
2
3
1
6
3
7
N
/
A
1
.
8
0
.
1
2
0
.
0
1
8/
5
/
0
8
0
.
0
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C
-
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0
.
1
2
9
.
3
1
2
9
1
0
.
6
4
.
7
6
2
%
7
.
1
3
1
2
7
N
/
A
3
8
0
.
1
2
0
.
0
1
8/
5
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0
8
0
.
0
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C
-
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2
.
4
2
9
.
3
1
2
9
3
0
.
6
4
.
7
6
2
%
7
.
0
6
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
8/
6
/
0
8
0
.
0
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C
-
1
3
0
.
1
3
1
.
0
6
0
9
5
4
3
6
.
1
5
.
7
9
3
%
7
.
8
1
1
5
5
9
.
3
0
.
0
1
0
.
0
1
8/
6
/
0
8
0
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0
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-
1
3
0
.
6
3
1
.
0
6
0
9
5
3
3
6
.
1
5
.
7
9
3
%
7
.
8
1
1
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
8/
6
/
0
8
0
.
0
F
C
-
4
0
.
1
3
0
.
9
6
1
5
5
4
3
6
.
6
6
.
3
1
0
3
%
8
.
0
4
5
5
8
.
1
0
.
0
1
0
.
0
1
8/
6
/
0
8
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-
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1
.
3
3
0
.
8
6
0
3
5
0
3
6
.
5
6
.
4
1
0
3
%
8
.
0
3
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
8/
6
/
0
8
0
.
0
F
C
-
6
0
.
1
3
0
.
2
6
0
9
7
2
3
6
.
6
6
.
2
1
0
1
%
8
.
0
2
5
5
8
.
0
0
.
0
1
0
.
0
1
8/
6
/
0
8
0
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-
6
1
.
2
3
0
.
1
6
1
0
0
2
3
6
.
6
6
.
3
1
0
1
%
8
.
0
3
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
8/
6
/
0
8
0
.
0
F
C
-
8
0
.
1
3
0
.
7
6
1
2
9
2
3
6
.
5
5
.
9
9
7
%
7
.
9
2
5
5
9
.
0
0
.
0
1
0
.
0
1
8/
6
/
0
8
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-
8
0
.
4
3
0
.
7
6
1
2
9
0
3
6
.
5
5
.
9
9
7
%
7
.
9
4
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
8/
6
/
0
8
0
.
0
F
C
-
F
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Y
0
.
1
3
1
.
2
6
0
4
8
3
3
5
.
6
6
.
1
9
9
%
7
.
9
8
5
5
1
0
.
4
0
.
0
1
0
.
0
1
8/
6
/
0
8
0
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1
.
0
3
0
.
9
6
1
0
3
0
3
6
.
2
6
.
0
9
8
%
7
.
9
1
4
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
8/
6
/
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8
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1
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1
.
9
4
9
3
8
8
3
4
.
3
5
.
7
7
8
%
7
.
9
3
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
10
/
1
5
/
0
8
0
.
0
F
C
-
F
O
Y
0
.
1
2
2
.
0
4
8
2
0
8
3
4
.
3
5
.
1
8
3
%
8
.
0
0
5
5
3
5
0
4
0
.
0
1
0
.
0
1
10
/
1
5
/
0
8
0
.
0
F
C
-
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Y
0
.
7
2
2
.
0
4
8
2
1
6
3
4
.
3
5
.
1
8
3
%
7
.
9
1
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
10
/
1
5
/
0
8
0
.
0
L
C
-
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R
0
.
1
2
2
.
4
2
7
1
1
4
2
2
.
4
5
.
3
6
7
%
7
.
4
0
6
3
1
N
/
A
5
0
.
1
5
0
.
0
4
10
/
1
5
/
0
8
0
.
0
L
C
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1
.
6
2
2
.
4
2
7
0
3
1
7
.
5
5
.
2
6
6
%
7
.
3
0
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
10
/
1
5
/
0
8
0
.
0
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T
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B
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0
.
1
2
2
.
7
3
3
4
0
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2
7
.
6
8
7
%
7
.
5
0
2
8
0
N
/
A
3
0
.
1
2
0
.
0
1
10
/
1
5
/
0
8
0
.
0
M
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T
-
N
B
0
.
1
2
0
.
2
3
1
8
0
.
2
5
.
8
6
4
%
7
.
4
0
9
1
0
N
/
A
2
0
.
1
7
0
.
0
1
10
/
1
5
/
0
8
0
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0
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C
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D
S
0
.
1
2
1
.
6
3
1
.
3
4
4
9
1
6
4
.
8
6
5
%
7
.
7
0
7
4
5
9
0
5
3
0
.
0
1
0
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0
1
10
/
1
5
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C
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D
S
0
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9
2
1
.
8
4
7
0
6
5
3
2
.
8
4
.
7
6
5
%
7
.
8
1
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
10
/
1
5
/
0
8
0
.
0
P
C
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D
U
S
0
.
1
2
2
.
1
3
7
5
3
8
2
5
.
4
4
.
2
5
5
%
7
.
5
0
1
9
5
4
1
0
5
0
.
0
2
0
.
0
3
10
/
1
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8
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.
0
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C
-
M
0
.
1
2
2
.
5
3
4
.
0
4
9
1
1
4
5
.
8
8
2
%
7
.
9
0
5
1
9
3
0
.
0
1
0
.
0
1
10
/
1
5
/
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8
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2
.
0
2
2
.
5
4
9
1
0
3
3
4
.
0
5
.
6
7
8
%
7
.
9
0
N
/
A
N
/
A
N
/
A
N
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/
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10
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6
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0
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1
1
9
.
2
2
5
4
0
.
1
3
.
3
3
6
%
7
.
1
2
1
0
N
/
A
3
0
.
0
9
0
.
0
2
10
/
1
6
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0
8
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0
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G
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H
1
.
1
1
9
.
1
2
4
8
0
.
1
3
.
0
3
3
%
7
.
1
2
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
10
/
1
6
/
0
8
0
.
0
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G
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L
0
.
1
2
1
.
1
3
6
0
0
.
2
3
.
1
3
5
%
7
.
2
1
1
6
3
N
/
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3
0
.
0
3
0
.
0
4
10
/
1
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G
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0
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1
1
8
.
8
1
6
4
0
.
1
1
.
4
1
5
%
6
.
7
4
4
N
/
A
8
0
.
0
2
0
.
0
3
10
/
1
6
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8
0
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0
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G
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3
.
0
1
7
.
6
3
0
4
0
.
2
0.
3
3
%
6
.
7
7
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
10
/
1
6
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0
8
0
.
0
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C
-
2
3
0
.
1
2
3
.
1
9
8
5
8
4
.
5
6
.
3
7
6
%
7
.
2
1
8
1
1
8
N
/
A
6
0
.
2
1
0
.
0
9
10
/
1
6
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0
8
0
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0
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C
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2
3
1
.
9
2
2
.
6
9
4
0
0
5
.
7
6
.
0
7
1
%
7
.
1
2
0
N
/
A
N
/
A
N
/
A
N
/
A
N
/
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10
/
1
6
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0
8
0
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C
-
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D
0
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1
2
0
.
7
2
4
7
0
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1
7
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9
8
8
%
7
.
1
0
1
1
8
2
N
/
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6
0
.
0
5
0
.
0
2
10
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1
6
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8
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0
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H
0
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1
2
3
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0
1
6
3
6
0
1
0
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0
6
.
1
7
5
%
7
.
1
8
2
8
N
/
A
5
0
.
2
7
0
.
0
3
10
/
1
6
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8
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2
.
1
2
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9
1
6
7
1
6
1
0
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3
6
.
1
7
5
%
7
.
1
1
1
N
/
A
N
/
A
N
/
A
N
/
A
N
/
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10
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1
6
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8
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0
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1
2
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2
2
1
8
0
.
1
6
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7
7
1
%
7
.
2
3
1
4
5
5
N
/
A
3
0
.
0
8
0
.
0
6
10
/
1
6
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8
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0
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1
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.
4
3
7
4
0
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2
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6
5
2
%
7
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1
0
1
1
8
N
/
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6
0
.
0
8
0
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1
10
/
1
6
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3
.
2
2
1
.
4
3
7
6
0
.
2
4
.
6
5
2
%
7
.
0
7
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
11
/
1
3
/
0
8
0
.
6
B
C
-
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B
R
0
.
1
1
8
.
0
8
8
0
.
1
6
.
8
7
2
%
7
.
5
1
5
2
3
0
0
N
/
A
4
0
.
0
7
0
.
0
1
11
/
1
3
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0
8
0
.
6
B
C
-
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R
2
.
3
1
8
.
0
8
8
0
.
1
6
.
9
7
3
%
7
.
4
1
9
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
11
/
1
3
/
0
8
0
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6
L
C
-
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R
0
.
1
1
7
.
1
2
9
3
3
0
2
1
.
8
7
.
5
8
9
%
6
.
9
7
1
3
6
N
/
A
4
0
.
2
3
0
.
0
5
11
/
1
3
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0
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0
.
6
L
C
-
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R
1
.
2
1
7
.
1
2
9
2
6
1
2
1
.
7
7
.
2
8
6
%
7
.
0
9
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
11
/
1
3
/
0
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0
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6
M
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T
-
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R
0
.
1
1
8
.
7
8
4
0
.
0
7
.
6
8
2
%
7
.
2
3
3
2
8
0
0
N
/
A
4
0
.
0
8
0
.
0
4
11
/
1
3
/
0
8
0
.
6
M
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T
-
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0
.
1
1
8
.
4
8
1
0
.
0
6
.
8
7
2
%
7
.
0
2
7
2
6
0
0
N
/
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3
0
.
0
7
0
.
0
5
11
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1
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5
P
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0
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1
1
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6
1
3
5
0
.
1
3
.
4
3
6
%
6
.
9
4
1
5
4
6
N
/
A
2
0
.
0
3
0
.
0
7
11
/
1
4
/
0
8
0
.
5
P
G
-
C
H
1
.
4
1
7
.
6
1
3
5
0
.
1
3
.
3
3
5
%
6
.
8
4
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
11
/
1
4
/
0
8
0
.
5
P
G
-
M
L
0
.
1
1
6
.
8
1
9
2
0
.
1
4
.
0
4
1
%
7
.
2
1
2
3
0
0
0
N
/
A
1
0
.
0
1
0
.
0
4
11
/
1
4
/
0
8
0
.
5
P
G
-
N
C
0
.
1
1
7
.
5
1
2
6
0
.
1
2
.
2
2
3
%
6
.
5
5
2
0
0
0
N
/
A
2
0
.
0
6
0
.
0
9
11
/
1
4
/
0
8
0
.
5
P
G
-
N
C
3
.
4
1
7
.
5
1
2
6
0
.
1
2
.
0
2
1
%
6
.
5
1
0
N
/
A
N
/
A
N
/
A
N
/
A
N
/
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11
/
1
4
/
0
8
0
.
5
S
C
-
2
3
0
.
1
1
6
.
5
5
4
4
0
3
.
6
6
.
8
7
1
7
.
2
9
5
4
6
N
/
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5
0
.
2
5
0
.
0
4
11
/
1
4
/
0
8
0
.
5
S
C
-
2
3
2
.
9
1
6
.
4
7
6
4
0
5
.
2
6
.
8
7
2
7
.
1
1
4
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
11
/
1
4
/
0
8
0
.
5
S
C
-
C
D
0
.
1
1
8
.
2
1
3
3
0
.
1
9
.
1
9
6
6
.
4
9
4
7
0
0
N
/
A
4
0
.
0
8
0
.
0
5
11
/
1
4
/
0
8
0
.
5
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C
-
C
H
0
.
1
1
6
.
4
1
5
7
9
2
1
1
.
3
6
.
8
7
4
%
7
.
1
1
2
1
9
9
N
/
A
3
0
.
5
3
0
.
0
5
11
/
1
4
/
0
8
0
.
5
S
C
-
C
H
2
.
9
1
6
.
3
1
6
5
3
0
1
1
.
9
6
.
7
7
4
%
7
.
1
3
7
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
11
/
1
4
/
0
8
0
.
5
S
C
-
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R
0
.
1
1
7
.
9
1
2
2
0
.
1
7
.
5
8
0
%
6
.
6
8
5
9
0
0
N
/
A
2
0
.
2
0
0
.
0
3
11
/
1
4
/
0
8
0
.
5
S
C
-
N
K
0
.
1
1
8
.
0
1
6
2
0
.
1
5
.
2
5
5
6
.
7
1
4
2
0
0
0
N
/
A
2
0
.
1
2
0
.
0
5
11
/
1
4
/
0
8
0
.
5
S
C
-
N
K
2
.
9
1
8
.
0
1
6
2
0
.
1
5
.
0
5
3
%
6
.
7
1
4
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
11
/
1
8
/
0
8
0
.
0
F
C
-
1
3
0
.
1
1
3
.
2
3
8
7
7
0
3
2
.
8
6
.
9
8
1
%
7
.
8
1
2
8
1
9
1
0
.
0
1
0
.
0
1
11
/
1
8
/
0
8
0
.
0
F
C
-
1
3
1
.
4
1
3
.
3
3
9
3
5
7
3
3
.
2
6
.
7
7
9
%
7
.
9
3
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
11
/
1
8
/
0
8
0
.
0
F
C
-
4
0
.
1
1
4
.
3
4
1
5
0
6
3
4
.
3
6
.
2
7
5
%
8
.
0
1
5
5
2
0
.
0
1
0
.
0
1
11
/
1
8
/
0
8
0
.
0
F
C
-
4
1
.
8
1
4
.
3
4
1
5
4
2
3
4
.
4
6
.
2
7
5
%
8
.
0
1
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
11
/
1
8
/
0
8
0
.
0
F
C
-
6
0
.
1
1
3
.
7
4
0
6
4
7
3
4
.
0
6
.
3
7
5
%
8
.
0
0
1
9
1
0
2
0
.
0
1
0
.
0
1
11
/
1
8
/
0
8
0
.
0
F
C
-
6
1
.
4
1
3
.
8
4
0
6
7
6
3
4
.
0
6
.
3
7
5
%
8
.
0
1
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
11
/
1
8
/
0
8
0
.
0
F
C
-
F
O
Y
0
.
1
1
3
.
2
3
9
1
2
0
3
3
.
1
6
.
5
7
6
%
7
.
9
0
5
1
9
1
0
.
0
1
0
.
0
1
11
/
1
8
/
0
8
0
.
0
F
C
-
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Y
1
.
2
1
3
.
4
3
9
7
8
8
3
3
.
5
6
.
5
7
6
%
7
.
9
0
N
/
A
N
/
A
N
/
A
N
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A
N
/
A
11
/
1
8
/
0
8
0
.
0
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C
-
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D
S
0
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1
1
3
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3
3
8
5
6
9
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2
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5
8
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6
1
0
0
%
7
.
9
4
7
2
8
7
2
8
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0
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0
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0
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11
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1
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1
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4
3
9
0
7
5
3
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.
9
6
.
1
7
2
%
7
.
9
1
3
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
11
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1
8
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8
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S
0
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1
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4
.
2
2
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3
5
4
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3
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4
5
.
0
5
7
%
7
.
7
6
6
4
3
3
0
4
0
.
0
1
0
.
0
1
11
/
1
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M
0
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1
1
3
.
9
4
0
5
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7
3
3
.
8
5
.
5
6
6
%
8
.
0
0
5
1
9
2
0
.
0
1
0
.
0
1
11
/
1
8
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1
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8
1
3
.
8
4
0
5
2
3
3
3
.
8
5
.
5
6
6
%
8
.
0
4
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
12
/
1
/
0
8
0
.
0
.
B
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-
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B
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0
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1
1
3
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8
1
6
1
0
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1
7
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4
7
1
%
7
.
4
0
1
0
0
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N
/
A
2
0
.
0
6
0
.
0
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12
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8
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0
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-
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R
1
.
3
1
3
.
8
1
4
7
0
.
1
7
.
4
7
1
%
7
.
3
4
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
12
/
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/
0
8
0
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0
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R
0
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1
1
2
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6
1
5
1
4
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9
5
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8
6
0
%
6
.
5
8
5
5
N
/
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3
0
.
3
1
0
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0
5
12
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1
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5
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2
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6
1
5
1
1
7
1
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8
5
.
9
6
0
%
6
.
6
9
N
/
A
N
/
A
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/
A
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N
/
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12
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1
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2
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8
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2
9
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2
9
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7
.
0
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1
7
2
8
N
/
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2
0
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1
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0
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12
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0
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8
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7
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1
7
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4
7
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6
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9
4
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9
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1
0
0
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1
2
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12
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1
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0
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6
5
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1
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3
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7
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4
1
3
6
4
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0
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5
0
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0
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1
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5
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1
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6
9
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1
7
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0
5
9
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7
.
3
1
5
N
/
A
N
/
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A
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12
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0
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0
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1
9
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4
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7
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2
6
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8
5
9
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7
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4
0
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9
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0
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5
0
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6
0
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1
12
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1
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5
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5
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1
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5
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9
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6
.
9
0
1
0
0
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2
0
.
0
4
0
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12
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3
.
3
7
.
6
1
4
1
0
.
1
2
.
9
2
4
%
6
.
8
0
N
/
A
N
/
A
N
/
A
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A
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/
A
12
/
3
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0
8
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C
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2
3
0
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1
1
1
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1
5
5
6
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4
8
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5
7
8
%
7
.
6
4
1
6
3
N
/
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4
0
.
1
1
0
.
0
3
12
/
3
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0
8
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2
3
2
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6
1
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.
2
5
5
7
0
.
4
8
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4
7
7
%
7
.
5
5
N
/
A
N
/
A
N
/
A
N
/
A
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/
A
12
/
3
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0
8
0
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0
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C
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0
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1
1
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.
2
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2
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1
9
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7
8
9
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6
.
9
2
2
8
0
N
/
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2
0
.
0
9
0
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0
1
12
/
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0
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1
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9
1
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1
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9
8
1
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7
.
6
6
3
7
N
/
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1
0
.
2
0
0
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0
6
12
/
3
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0
8
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0
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2
.
4
1
0
.
9
1
9
0
6
1
.
4
8
.
6
7
9
%
7
.
5
1
8
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
12
/
3
/
0
8
0
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0
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C
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0
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1
1
0
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8
1
2
3
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1
9
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9
9
0
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7
.
0
1
2
9
0
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/
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2
0
.
0
7
0
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0
1
12
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1
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0
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1
1
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2
1
8
0
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1
8
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8
7
9
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6
.
9
2
9
1
N
/
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2
0
.
1
5
0
.
0
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12
/
3
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2
.
5
1
0
.
2
1
7
9
0
.
1
8
.
5
7
6
%
6
.
9
2
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
12
/
4
/
0
8
0
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0
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-
1
3
0
.
1
1
1
.
0
3
3
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2
2
2
9
.
5
5
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8
6
5
%
7
.
7
0
5
1
9
0
.
5
0
.
0
1
0
.
0
1
12
/
4
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1
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8
1
1
.
0
3
3
9
7
4
3
0
.
0
5
.
9
6
6
7
.
8
0
N
/
A
N
/
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N
/
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N
/
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/
A
12
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4
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0
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4
0
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1
1
1
.
6
3
8
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3
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3
3
.
8
5
.
8
6
5
%
8
.
0
0
5
5
1
0
.
0
1
0
.
0
1
12
/
4
/
0
8
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0
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-
4
2
.
0
1
1
.
5
3
8
5
6
7
3
4
.
1
5
.
0
5
5
%
8
.
0
0
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
12
/
4
/
0
8
0
.
0
F
C
-
6
0
.
1
1
1
.
5
3
7
7
3
7
3
3
.
3
5
.
3
6
0
%
7
.
9
0
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5
1
0
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0
1
0
.
0
1
12
/
4
/
0
8
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0
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-
6
1
.
3
1
1
.
5
3
7
9
4
2
3
3
.
4
5
.
3
6
0
%
8
.
0
0
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
12
/
4
/
0
8
0
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0
F
C
-
F
O
Y
0
.
1
1
1
.
1
3
4
4
1
2
3
0
.
3
5
.
8
6
5
7
.
9
0
5
5
2
0
.
0
6
0
.
0
1
12
/
4
/
0
8
0
.
0
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C
-
F
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Y
1
.
1
1
1
.
1
3
5
8
5
4
3
1
.
7
5
.
6
6
0
7
.
9
0
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
12
/
4
/
0
8
0
.
0
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C
-
B
D
D
S
0
.
1
1
0
.
5
3
5
3
5
5
3
1
.
7
6
.
5
7
2
%
7
.
9
0
5
6
0
1
2
7
2
0
.
0
1
0
.
0
1
12
/
4
/
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8
0
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0
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C
-
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D
S
1
.
0
1
0
.
8
3
6
1
8
6
3
2
.
4
6
.
5
7
2
%
7
.
9
0
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
12
/
4
/
0
8
0
.
0
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C
-
B
D
U
S
0
.
1
1
4
.
3
2
2
0
2
5
1
7
.
2
6
.
0
6
.
8
%
7
.
7
0
9
1
1
1
8
1
0
.
0
1
0
.
0
1
12
/
4
/
0
8
0
.
0
P
C
-
M
0
.
1
1
1
.
9
3
8
7
7
9
3
3
.
9
6
.
0
6
8
%
8
.
0
0
1
0
5
1
0
.
0
1
0
.
0
1
12
/
4
/
0
8
0
.
0
P
C
-
M
1
.
5
1
1
.
9
3
8
8
3
0
3
3
.
9
6
.
0
6
8
%
8
.
0
1
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
1/
1
2
/
0
9
0
.
0
B
C
-
C
B
R
0
.
1
1
1
.
7
1
7
0
0
.
1
8
.
3
7
7
%
6
.
9
0
8
1
8
N
/
A
4
.
0
0
.
1
5
0
.
0
2
1/
1
2
/
0
9
0
.
0
L
C
-
R
R
0
.
1
1
0
.
4
2
7
9
0
2
.
1
1
0
.
8
9
7
%
5
.
9
1
1
2
3
0
N
/
A
3
0
.
3
7
0
.
0
7
1/
1
2
/
0
9
0
.
0
L
C
-
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R
1
.
3
1
0
.
4
5
4
0
9
4
.
2
1
0
.
5
9
6
%
6
.
0
1
2
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
1/
1
2
/
0
9
0
.
0
M
O
T
-
C
B
R
0
.
1
1
3
.
0
3
1
5
0
.
2
8
.
4
8
0
%
6
.
6
9
5
8
0
N
/
A
1
0
.
0
1
0
.
0
1
1/
1
2
/
0
9
0
.
0
M
O
T
-
N
B
0
.
1
1
1
.
8
2
8
1
0
.
2
8
.
1
7
5
%
6
.
7
9
1
0
9
1
N
/
A
4
.
0
0
.
0
7
0
.
0
3
1/
1
3
/
0
9
0
.
5
P
G
-
C
H
0
.
1
8
.
4
2
1
3
0
.
2
7
.
5
6
4
%
7
.
2
1
1
1
8
2
N
/
A
1
0
.
0
5
0
.
0
5
1/
1
3
/
0
9
0
.
5
P
G
-
C
H
1
.
5
8
.
4
2
1
3
0
.
2
7
.
2
6
2
%
7
.
1
1
1
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
1/
1
3
/
0
9
0
.
5
P
G
-
M
L
0
.
1
9
.
6
2
5
0
0
.
2
8
.
2
7
2
%
7
.
3
0
6
3
7
N
/
A
1
0
.
0
1
0
.
0
4
1/
1
3
/
0
9
0
.
5
P
G
-
N
C
0
.
1
8
.
2
1
8
2
0
.
1
4
.
8
4
1
%
6
.
9
0
3
7
N
/
A
1
0
.
0
1
0
.
0
4
1/
1
3
/
0
9
0
.
5
P
G
-
N
C
3
.
7
8
.
6
2
9
2
0
.
2
2
.
2
1
9
%
6
.
8
4
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
1/
1
3
/
0
9
0
.
5
S
C
-
2
3
0
.
1
1
1
.
3
3
8
1
0
.
3
9
.
3
8
5
%
7
.
3
1
0
1
4
5
N
/
A
2
0
.
0
1
0
.
0
6
1/
1
3
/
0
9
0
.
5
S
C
-
2
3
2
.
8
1
1
.
3
3
7
3
0
.
3
9
.
2
8
4
%
7
.
3
1
2
N
/
A
N
/
A
N
/
A
N
/
A
N
/
A
1/
1
3
/
0
9
0
.
5
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7
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7
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9
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6
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8
3
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6
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8
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6
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8
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2
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2
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6
8
7
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6
.
7
1
1
N
/
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6
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6
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4
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6
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6
1
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8
1
9
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/
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3
6
0
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0
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1
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4
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5
1
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1
8
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2
8
4
%
6
.
6
1
5
N
/
A
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/
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/
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1
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6
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9
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1
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1
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5
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7
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7
7
5
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6
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7
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5
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/
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1
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7
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2
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5
7
3
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6
.
8
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N
/
A
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A
Sources of Fecal Bacterial Pollution to Upper Pages Creek, N.C.
UNCW-CMS Report 09-01
By
Michael A. Mallin, Ph.D.1, Mary I.H. Spivey1 and Bongkeun Song, Ph.D.2
1University of North Carolina Wilmington
Center for Marine Sciences
Wilmington, N.C. 28409
mallinm@uncw.edu
2Department of Biology and Marine Biology
University of North Carolina Wilmington
January 13, 2009
Report to:
Coastal Planning & Engineering of North Carolina, Inc.
4038 Masonboro Loop Rd., Wilmington, N.C. 28409
Introduction
Pages Creek is a 3rd order tidal creek located in northern New Hanover County, North Carolina. Whereas most
of the tidal creeks in the area are closed to shellfishing due to excessive fecal coliform bacteria counts, Pages
Creek, along with nearby Futch Creek, remains partially open to shellfishing. This is likely a result of its low
percentage of developed land, in particular its low percent impervious surface coverage, compared with other
area tidal creeks (Mallin et al. 2000). For twelve years this creek was sampled as a part of the New Hanover
County Tidal Creeks Program, funded by New Hanover County with sampling and analyses carried out by the
Aquatic Ecology Laboratory at the University of North Carolina Wilmington’s Center for Marine Science. That
program indicated that some areas of the creek have periodically experienced fecal bacterial pollution, including
the uppermost stations PC-BDUS and PC-H (Figure 1) and a tributary location PC-BDDS (Figure 1). Data
from 1995, 2001 and 2007 showed periodic high concentrations (especially in 1995 and 2007) of fecal coliform
bacteria exceeding the North Carolina recreational water standard of 200 colony-forming units (CFUs) per 100
mL of water (Table 1). Also, an elevated count found by UNCW in June 2007 at PC-H, near the headwaters
prompted investigations by County planners and engineers that located a sewage pump station problem that was
subsequently rectified. We note that human signals of fecal pollution have recently been identified from Pages
Creek (Spivey 2008).
Table 1. Fecal coliform bacteria data (presented as geometric mean and range) for upper Pages Creek, North
Carolina.
______________________________________________________________________________
Station 1995 2001 2007
______________________________________________________________________________
PC-BDUS 260 (40-3,001) 38 (10-140) 131 (29-1,040)
PC-BDDS 155 (17-1,020) 28 (3-126) 38 (21-1536)
PC-H 63 (10-575) 29 (7-200) 34 (21-309)
______________________________________________________________________________
As of 2008 the Tidal Creeks Program was no longer funded by the County; subsequent County-sponsored
sampling of this creek was performed by Coastal Planning & Engineering of North Carolina, Inc. Elevated
fecal coliform bacteria counts in upper creek areas continued to be found during sampling by this group. As
such, in fall 2008 UNCW was contracted by Coastal Planning & Engineering to perform bacteria source
tracking using molecular-based methods. The work was carried out as a collaborative effort between the
Aquatic Ecology Laboratory, led by Dr. Michael Mallin, and Dr. Bongkeun Song of the UNCW Department of
Biology and Marine Biology.
Site Description
Two stations were sampled in upper Pages Creek, PC-BDUS and PC-BDDS (Figure 1).
PC-BDUS is located in the upper portion of Pages Creek, and is fed by a drainage ditch/intermittent stream that
drains a large suburban area encompassing a portion of Bayshore Drive and a development across Highway 17
as well (Figure 2). There is also a sewage pump station located at this site, as well as a concrete boat ramp
(Figure 2). A spring feeds the creek near this location as well.
2
PC-BDDS is located at the headwaters of a 1st order tributary to Pages Creek along its northern shore. This
tributary is fed by a stormwater drainpipe that carries runoff water under Bayshore Drive from an adjacent
suburban area (Figure 3). There is also a sewage lift station located at the sampling location.
Materials and Methods
Samples were collected by Coastal Planning & Engineering and UNCW personnel from each station on four
separate dates in 2008: September 23, October 15, November 4, and December 11. The latter two samples
were collected during or just after substantial rain events; the first two samples were collected in relatively dry
periods. Water samples were collected at each station for mean fecal coliform and mean Enterococcus counts,
optical brightener analysis, and DNA extraction.
Water samples from both stations were collected in autoclaved 500mL Pyrex glass bottles. The samples were
transported on ice and allowed to sit no longer than six hours before filtration. Upon return to the lab, 500 mL
of water were filtered on Whatman GF/F 47 mm filters (nominal pore size 0.7 µm) using autoclaved glassware
for DNA extraction. The samples were stored at -20°C until DNA was extracted. The fecal coliform and
Enterococcus samples were filtered using autoclaved glassware and sterile Millipore white gridded 47mm
filters, with a nominal pore size of 0.45µm. For mean fecal coliform (MFC) analysis, these filters were placed
in sterile petri dishes with pads soaked in MFC broth media, composed of MFC medium, distilled water, and
Rosolic Acid solution (Rosolic Acid crystals dissolved in 0.2N NaOH). The plates were then sealed in plastic
storage bags and incubated in a water bath at 44.5°C for 23 to 25 hours. For mean Enterococcus (ME), the
filters were placed in sterile petri dishes with ME agar, composed of ME agar media, nalidixic acid, and a 1%
solution 2,3,5-triphenyl tetrazolium solution. The plates were also sealed in plastic storage bags and incubated
in a water bath at 41.0°C for 47 to 49 hours. Both the MFC and ME samples were removed from the incubator
after the specified period of time, colonies that formed on the gridded filters were counted, and the counts were
reported as an average of the number of colony forming units (CFUs) per 100mL of water. See APHA (1995)
for detailed methodologies.
DNA Extraction: DNA was extracted using the PowerSoilTM DNA Isolation Kit from MO BIO Laboratories,
with some modification for filter exttraction. A portion of the filter was ground using a PowerBead Tube and
tissue grinder, and then the extraction was completed per manufacturer’s instructions. The DNA Isolation Kit
uses a detergent to lyse the cells and release the DNA, and uses several solutions to help precipitate materials
that may reduce the purity of the DNA (such as non-DNA humics, cell debris, and proteins). The completed
process results in 100µL of DNA for use in any downstream applications.
PCR: Initial PCR was conducted with the universal 16s primers for eubacteria to amplify the DNA of any
bacteria present in the sample. The first PCR reaction mixtures were then used as template for the second PCR
reaction for each sample. The second PCR mixtures were then set up with a Bac32F/Bac708R primer pair, in
which the forward primer (Bac32F) was labeled with fluorescent tags (5’6’-FAM labeled).
The second PCR products were run on a 1% agarose gel to determine the presence or absence of the expected
sizes of DNA frqagments (675 bp) and to separate the targeted size fragments from others. The second
amplified products were cut out from the gel and then a GENECLEAN® Turbo Kit (Q-BIO gene) was used to
purify the fragments from the agarose gels as following manufacturer’s instructions. The concentration of
purified PCR products was measured using a Quant-iTTMDNA HS Assay (Invitrogen) and a Qubit fluorometer.
3
T-RFLP: In order to determine the sources of bacteria contamination, terminal restriction fragment
polymorphism (T-RFLP) analysis was conducted with the purified PCR amplicons. A total of 20 ng of PCR
fragments were used for restriction enzyme digestion. These reactions were incubated overnight at 37°C. The
digestion mixtures were then precipitated with 75% isopropanol and resuspended with a mixture of HiDi
formamide and GS 500 Rox (a size standard) for DNA fingerprinting. The samples were run on the ABI
PRISM® Genetic Analyzer and analyzed with the Genemapper program (ABI). Upon completion of
fingerprinting, each sample was represented by a profile. The profiles have representative peaks (T-RFs) for
each of the bacterial populations represented in the samples (Figures 4-6). The size of each T-RF present is
indicated in base pairs, and can be matched to known 16rRNA genes in the NCBI database using the Microbial
Community Analysis 3 (MiCA) T-RFLP Analysis Phylogenetic Assessment Tool (PAT)
(http://mica.ibest.uidaho.edu/pat.php) to identify the sources of bacterial contamination.
Relative quantification of bacterial contamination sources was determined based on the height of each T-RF.
The percent abundance was calculated as a sum of each T-RF from the same sources.
Optical brighteners, compounds added to laundry detergents, adsorb to clothing and form a light reflective layer
creating the appearance of whiter whites and brighter colors. These compounds are excited by light in the near
UV range (360-365nm) and emit light in the blue range (400-440nm). After light absorption, fluorescence is
given off during the second excited state and can be measured by a fluorometer. In the United States, 97% of
all laundry detergents contain one or both of two types of fluorescent whitening agents; FWA-1 also called
DAS1 or FB-28, or FWA-2 referred to as DSBP or Tinopal CBS-X. Since household plumbing systems
combine wastewater from toilets and washing machines, the presence of optical brighteners and fecal coliform
bacteria in a waterway may indicate an input of human origin. Optical brightener samples were collected by
filling Nalgene 125mL opaque collection bottles 10 cm below the surface facing into the stream. Collection
bottles were acid washed and triple rinsed before sampling. Samples were refrigerated in the dark at 8º C and
read within 8 days.
Fluorometry was performed with a laboratory fluorometer (Model 10-AU-000, Turner Designs, Sunnyvale,
California). A kit was added to the fluorometer that included a lamp (10-049) emitting near UV light at 310-390
nm, a filter (10-069R) for the 300-400nm light range, and finally a 436 nm filter was added to greater decrease
background fluorescence (Hartel 2007a). A standard curve was created using serial dilutions from 100 mg of
Tide (Procter and Gamble, Cincinnati, Ohio) in one liter of deionized water. Tide is a commonly used laundry
detergent known to contain optical brighteners. When the fluorometer was adjusted to an 80% sensitivity scale,
the fluorometric value of 100 was equal to 100mg of Tide in 1 L of deionized water. The standard curve
demonstrated that there was a linear relationship between the fluorometric response and detergent-sourced
optical brighteners up to a reading of 100. Following field collections, each field sample was read on the
fluorometer in triplicate at room temperature after 10 seconds to minimize degradation of optical brighteners by
UV light (Hartel 2007b; Tavares et al. 2008). For optical brightener determination, the samples were allowed to
warm to room temperature for approximately 30 minutes. Each sample was shaken and poured into a cuvette
(about 1/3 full). The cuvette was then placed in the fluorometer modified as above for optical brightener
measurement.
4
Results
Fecal coliform bacteria: Sampling indicated a fecal coliform bacterial pollution problem at Stations PC-BDUS
and PC-BDDS in fall 2008 (Table 2). While both sites were polluted, PC-BDDS tended to have higher fecal
coliform counts than PC-BDUS, especially during the rainy period collections
Enterococcus bacteria: The Enterococcus counts all exceeded the instantaneous standard for marine
recreational waters of 104 CFU/100 mL (Table 2). During the rain dates the counts were especially high, 10-
30X the standard. Enterococcus counts were on average higher than fecal coliform bacteria counts, likely a
result of this indicator bacterium’s greater tolerance to elevated salinity in estuaries.
Optical brighteners: Elevated optical brightener (OB) concentrations are a good indication of sewage or septic
system pollution entering a water body (Hartel et al. 2007a). Based on our earlier investigations in local tidal
creeks OB concentrations above 20 were positively correlated with high fecal coliform bacteria counts in
reaches known to have been polluted by leaking sewer lines (Tavares et al. 2008). One sample, at PC-BDDS in
November registered 43, which we consider a strong signal of human sewage (Table 2). The sample from
November from Station PC-BDUS was about 22, indicated a good probability of sewage influence (Table 2).
The December OB samples were in the 49 to 54 range, again what we consider indicative of sewage or septic
influence (Table 2). While runoff of humic materials into the creek can cause some interference, most of this
should be filtered out by the adaptations to the fluorometer explained in the methods. The strong relationship
between OBs and high fecal bacteria counts is a good indication of a human infrastructure problem (hartel et al.
2007a, 2007b; Tavares et al. 2008).
Table 2. Fecal coliform bacteria, Enterococcus bacteria, and optical brightener data for upper Pages Creek,
September-December 2008.
__________________________________________________________________________________________
Date Fecal coliforms Enterococcus Optical brighteners
BDUS BDDS BDUS BDDS BDUS BDDS
__________________________________________________________________________________________
9/1/08 214 115 324 147 nd nd
10/15/08 410 905 195 745 13.7 15.4
11/4/08 765 2,320 1,720 2,970 21.8 43.1
12/11/08 1,065 2,175 3,830 3,175 49.6 53.9
Average 614 1,379 1,517 1,759
Geomean 517 851 803 1,008
__________________________________________________________________________________________
nd = no data
Sources of fecal bacteria pollution: There was a substantial human signal in the fecal bacteria collected from
upper Pages Creek in fall 2008 (Table 3; see also Figures 4-6). The human signal was higher at PC-BDDS than
PC-BDUS. The human signal at PC-BDDS was elevated both during a dry period sampling (September) as
well as during one of the wet period samplings (November).
In addition to the human signals, substantial ruminant signal was also found; again, the signal was greater at
PC-BDDS than PC-BDUS (Table 3; Figs. 4-6).
5
Table 3. Human and ruminant signal as a percent of fecal bacteria groups genetic profile for upper Pages Creek,
September-December 2008 (see also Figures 4-6).
__________________________________________________________________________________________
Human Ruminant
__________________________________________________________________________________________
Date BDUS BDDS BDUS BDDS
__________________________________________________________________________________________
9/1/08 17.2 30.7 18.7 42.1
10/15/08 13.2 12.6 13.9 18.2
11/4/08 13.8 21.5 19.8 26.4
12/11/08 ns 11.7 ns 18.1
__________________________________________________________________________________________
ns = no species-specific peaks
Conclusions
1) Both sites, during all four months, showed excessive fecal bacteria counts, either from fecal coliform bacteria
or Enterococcus bacteria, or both.
2) Fecal bacteria numbers were considerably higher at both sites during or shortly after rain events. Average
counts for the dry periods combined for fecal coliforms were 312 for PC-BDUS and 510 for PC-BDDS,
respectively, while for the rainy periods they were 915 and 2,248 CFU/100 mL for those two stations. For
Enterococcus average counts for PC-BDUS and PC-PDDS in dry periods were 260 and 446, respectively, while
for those same sites in wet periods they were 2,775 and 3,075 CFU/100 mL.
3) Station PC-BDDS had on average higher fecal bacteria counts than did PC-BDUS.
4) Optical brightener concentrations indicated that, at least some periods, either sewage or septic system
leachate was polluting the creek waters. What is especially perplexing is the elevated OB concentrations during
the rain events in November and December. While elevated counts can be expected from stormwater runoff
during rains, the elevated OB concentrations may point to a sewage system problem exacerbated by rainfall.
5) PCR and T-RFLP indicated the presence, sometimes substantial, of human fecal bacteria in Pages Creek at
both sites during all four months.
6) There was a considerable ruminant contribution to the fecal bacteria in upper Pages Creek as well. Likely
ruminant sources are deer, which are certainly present in the watershed, and horses if there any boarded in the
watershed. Regardless, the elevated ruminant signal points toward a non-point source (i.e. stormwater runoff)
pollution problem.
7) A number of unidentified peaks were also found, indicating other potential sources to those we list above.
8) These data collectively indicate that upper Pages Creek has a fecal bacteria problem with stormwater runoff
(as exemplified by the ruminant signal). There is also clearly a human infrastructure problem as well, either
derived from the pump stations present at the sites (particularly at PC-BDDS), leaking sewer lines, or possibly
failing septic systems if they are present in the upper Pages Creek watershed.
6
References
APHA. 1995. Standard Methods for the Examination of Water and Wastewater, 19th ed. American Public
Health Association, Washington, D.C.
Hartel, P.G., McDonald, J.L., Gentit, L.C., Hemmings, S.N., Rodgers, K., Smith, K.A., Belcher, C.N., Kuntz,
R.L., Rivera-Torres, Y., Otero, E., Schrōder, E.C. 2007a. Improving fluorometry as a source tracking method to
detect human fecal contamination. Estuaries and Coasts 30:1-11.
Hartel, P.G., Hagedorn, C.,McDonald, J.L., Fisher, J.A., Saluta, M.A., Dickerson Jr., J.W., Gentit, L.C., Smith,
S.L., Mantripragada, N. S., Ritter, K. J., Belcher, C.N. 2007b. Exposing water samples to ultraviolet light
improves fluorometry for detecting human fecal contamination. Water Research 41:3629-3642.
Mallin, M.A., K.E. Williams, E.C. Esham and R.P. Lowe. 2000. Effect of human development on
bacteriological water quality in coastal watersheds. Ecological Applications 10:1047-1056.
Spivey, M.I.H. 2008. The use of PCR and T-RFLP as means of identifying sources of fecal bacteria pollution in
the tidal creeks of New Hanover County, North Carolina. MS Thesis, the University of North Carolina
Wilmington.
Tavares, M.E., M.I.H. Spivey, M.R. McIver and M.A. Mallin. 2008. Testing for optical brighteners and fecal
bacteria to detect sewage leaks in tidal creeks. Journal of the North Carolina Academy of Science 124:91-97.
7
Figure 1. Pages Creek watershed and sampling sites.
8
Figure 2. Station PC-BDUS on Pages Creek, upper right – inflow pipe, lower left – Pump Station 79, lower
right – upstream inflow.
Figure 3. Station PC-BDDS on Pages Creek, upper right – inflow pipe, lower left – Pump Station 80, lower
right – upstream inflow.
9
Figure 4. Pages Creek DNA source profiles: September 2008
494:
491:161:
489:
484:104:
491:
489:
484:
161:
PC-BDDS (Top Profile):
The identified human peaks account for roughly 30.7% of the bacterial groups present; ruminant accounts
for 42.1%. Some large peaks are thus far unidentifiable, namely in the 225-227 range.
PC-BDUS (Bottom Profile):
The identified human peaks account for roughly 17.2% of the bacterial groups present; ruminant accounts
for 18.7%. Some large peaks are thus far unidentifiable, namely in the 219-227 range.
10
Figure 5. Pages Creek DNA source profiles: October 2008
495:163:
104:492:
161:489:
164:492:
490:
485:
PC-BDDS (Top Profile):
The identified human peaks account for roughly 12.6% of the bacterial groups present, human/avian roughly
8.4% (specific to both species), and ruminant accounts for 18.2%.
Some large peaks are thus far unidentifiable, namely in the 219-227 range.
PC-BDUS (Bottom Profile):
The identified human peaks account for roughly 13.2% of the bacterial groups present, and ruminant
accounts for 13.9%. Some large peaks are thus far unidentifiable, namely in the 50-133 range and the 219-228
range.
11
Figure 6. Pages Creek DNA source profiles: November 4 (top) and December 11 , 2008 (bottom).
104: Human 227: Ruminant
161:
Bacteroides
164: Human
157: Human
485: Human
48 an 9: Hum
492: Human
494:
Human/
Ri
PC-BDUS
PC-BDDS
494:
Human/
Ri
227: Ruminant
PC-BDUS
494:
Human/
Ruminant
PC-BDDS
104: Human
157: Human
163:
Human/
Ai 227: Ruminant
165: Human
490: Human
492: Human
The November and December percentages are:
BDDS (November): 21.5% Human
26.4% Ruminant
BDUS (November): 13.8% Human
19.8% Ruminant
BDDS (December): 11.7% Human
18.1% Ruminant
BDUS (December): No species-specific peaks
12