Environmental Assessment of the Lower
Cape Fear River System, 2006
By
Michael A. Mallin, Matthew R. McIver and James F. Merritt
December 2007
CMS Report No. 07-02
Center for Marine Science
University of North Carolina Wilmington
Wilmington, N.C. 28409
Executive Summary
Multiparameter water sampling for the Lower Cape Fear River Program (LCFRP) has
been ongoing since June 1995. Scientists from the University of North Carolina
Wilmington (UNCW) perform the sampling effort. The LCFRP currently encompasses
36 water sampling stations throughout the Cape Fear, Black, and Northeast Cape Fear
River watersheds. The LCFRP sampling program includes physical, chemical, and
biological water quality measurements and analyses of the benthic and epibenthic
macroinvertebrate communities, and has in the past included assessment of the fish
communities. Principal conclusions of the UNCW researchers conducting these
analyses are presented below, with emphasis on the period January - December 2006.
The opinions expressed are those of UNCW scientists and do not necessarily reflect
viewpoints of individual contributors to the Lower Cape Fear River Program.
The mainstem lower Cape Fear River is characterized by periodically turbid water
containing moderate to high levels of inorganic nutrients. It is fed by two large
blackwater rivers (the Black and Northeast Cape Fear Rivers) that have low levels of
turbidity, but highly colored water with less inorganic nutrient content than the
mainstem. While nutrients are reasonably high in the river channels, algal blooms are
rare because light is attenuated by water color or turbidity, and flushing is high. Periodic
algal blooms are seen in the tributary stream stations, some of which are impacted by
point source discharges. Below some point sources, nutrient loading can be high and
fecal coliform contamination occurs. Other stream stations drain blackwater swamps or
agricultural areas, some of which periodically show elevated pollutant loads or effects.
Average annual dissolved oxygen (DO) levels at the river channel stations for 2006
were similar to the average for 1996-2005. Dissolved oxygen levels were lowest during
the summer, often falling below the state standard of 5.0 mg/L at several river and
upper estuary stations. There is a dissolved oxygen sag in the main river channel that
begins at Station DP below a paper mill discharge and near the Black River input, and
persists into the mesohaline portion of the estuary. Mean oxygen levels were highest at
the upper river stations NC11 and AC and in the middle to lower estuary at stations M23
and M18. Lowest mainstem mean 2006 DO levels occurred at the lower river and
upper estuary stations NAV, HB, BRR and M61 (6.7-6.8 mg/L). As the water reaches
the lower estuary higher algal productivity, mixing and ocean dilution help alleviate
oxygen problems.
The Northeast Cape Fear and Black Rivers generally have lower DO levels than the
mainstem Cape Fear River. These rivers are classified as blackwater systems because
of their tea colored water. The Northeast Cape Fear River in general seems to be more
oxygen stressed than the Black River; in 2006 Station NCF117 had DO concentrations
below 4.0 mg/L 33% of the time sampled, while during that same period Station B210
had DO below 4.0 mg/L 0% of the occasions sampled. Several stream stations were
severely stressed in terms of low dissolved oxygen during the year 2006. Station GS
had DO levels below 4.0 mg/L 50% of the occasions sampled, NC403 33%, SR 33%
and ANC 25%. Smith Creek had DO levels below 5.0 mg/L 36% of the time.
Annual mean turbidity levels for 2006 were considerably lower than the long-term
average, probably a result of low rainfall. Highest mean turbidities were at NAV, then
the upper river sites N11 and AC (15-18 NTU) with turbidities gradually decreasing
downstream through the estuary. Turbidity was lower in the blackwater tributaries
(Northeast Cape Fear River and Black River) than in the mainstem river.
Regarding stream stations, chronic or periodic high nutrient levels were found at a number of
sites, including BC117, 6RC, GCO,NC403 and PB. Algal blooms were rare in 2006, only
occurring in July and August at Stations GS, PB, LRC and BCRR. Several stream stations,
particularly BCRR, BC117, HAM, SAR, PB , ROC, and LRC showed high fecal coliform counts
on a number of occasions. On a few occasions biochemical oxygen demand (BOD)
concentrations in several Northeast Cape Fear River watershed stream stations (especially N403
and BC117, were elevated (BOD5 greater than 2.5 mg/L). Water column metals concentrations
were not problematic during 2006.
This report includes an in-depth look at each subbasin, comparing the results of the
North Carolina Division of Water Quality's 2005 Basinwide Management Plan use
support ratings with the UNCW-Aquatic Ecology Laboratory’s (AEL) assessments of the
2006 sampling year. The UNCW-AEL utilized ratings that consider a water body to be
of poor quality if the water quality standard for a given parameter is in violation > 25% of
the time, of fair quality if the standard is in violation between 11 and 25% of the time,
and good quality if the standard is violated no more than 10% of the time. UNCW also
considerers nutrient loading in water quality assessments, based on published
experimental and field scientific findings.
For the 2006 period UNCW rated all stations as good in terms of chlorophyll a. For
turbidity 100% of the sites were rated good. However, 57% of the stations had either
fair or poor water quality in terms of fecal coliform bacterial contamination – more
than double that of 2005. Using the 5.0 mg/L DO standard for the Piedmont river
stations, and the 4.0 mg/L “swamp water” DO standard for the stream stations and
blackwater river stations, 47% of the sites were rated poor or fair for dissolved oxygen,
slightly more than in 2005. In addition, by our UNCW standards excessive nitrate and
phosphorus concentrations were problematic at a number of stations (Chapter 3).
Table of Contents
1.0 Introduction...........................................................................………...............…........1
1.1 Site Description................................................………....................................2
1.2 Report Organization………………………………………………………………..2
2.0 Physical, Chemical, and Biological Characteristics of the Lower Cape Fear River
and Estuary………………………………………………..…………………….....….. ….8
Physical Parameters..…......................………..........................................……....11
Chemical Parameters…....……..……….........................................................…..14
Biological Parameters.......……….....……......................................................…..17
3.0 Water Quality by Subbasin in the Lower Cape Fear River System…………………49
1.0 Introduction
Michael A. Mallin
Aquatic Ecology Laboratory
Center for Marine Science
University of North Carolina Wilmington
The Lower Cape Fear River Program is a unique science and education program that
has a mission to develop an understanding of processes that control and influence the
ecology of the Cape Fear River, and to provide a mechanism for information exchange
and public education. This Program provides a forum for dialogue among the various
Cape Fear River user groups and encourages interaction among them. Overall policy is
set by an Advisory Board consisting of representatives from citizen’s groups, local
government, industries, academia, the business community, and regulatory agencies.
This report represents the scientific conclusions of the UNCW researchers participating
in this Program and does not necessarily reflect opinions of all other Program
participants. This report focuses on the period January through December 2006.
The scientific basis of the Program consists of the implementation of an ongoing
comprehensive physical, chemical, and biological monitoring program. Another part of
the mission is to develop and maintain a data base on the Cape Fear basin and make
use of this data to develop management plans. Presently the Program has amassed a
ten-year (1995-2005) data base freely available to the public. Using this monitoring
data as a framework the Program goals also include focused scientific projects and
investigation of pollution episodes. The scientific aspects of the Program are carried out
by investigators from the University of North Carolina Wilmington Center for Marine
Science. The monitoring program was developed by the Lower Cape Fear River
Program Technical Committee, which consists of representatives from UNCW, the
North Carolina Division of Water Quality, The NC Division of Marine Fisheries, the US
Army Corps of Engineers, technical representatives from streamside industries, the City
of Wilmington Wastewater Treatment Plants, Cape Fear Community College, Cape
Fear River Watch, the North Carolina Cooperative Extension Service, the US
Geological Survey, forestry and agriculture organizations, and others. This integrated
and cooperative program was the first of its kind in North Carolina.
Broad-scale monthly water quality sampling at 16 stations in the estuary and lower river
system began in June 1995 (directed by Dr. Michael Mallin). Sampling was increased
to 34 stations in February of 1996, 35 stations in February 1998, and 36 stations in
2005. The Lower Cape Fear River Program added another component concerned with
studying the benthic macrofauna of the system in 1996. This component is directed by
Dr. Martin Posey and Mr. Troy Alphin of the UNCW Biology Department and includes
the benefit of additional data collected by the Benthic Ecology Laboratory under Sea
Grant and NSF sponsored projects in the Cape Fear Estuary. The third major biotic
component (added in January 1996) was an extensive fisheries program directed by Dr.
Mary Moser of the UNCW Center for Marine Science Research, with subsequent (1999)
overseeing by Mr. Michael Williams and Dr. Thomas Lankford of UNCW-CMS. This
1
program involved cooperative sampling with the North Carolina Division of Marine
Fisheries and the North Carolina Wildlife Resources Commission. The fisheries
program ended in December 1999, but was renewed with additional funds from the Z.
Smith Reynolds Foundation from spring – winter 2000, and has been operational
periodically for special projects since that period. The regular sampling that was
conducted by UNCW biologists was assumed by the North Carolina Division of Marine
Fisheries.
1.1 Site Description
The mainstem of the Cape Fear River is formed by the merging of the Haw and the
Deep Rivers in Chatham County in the North Carolina Piedmont. However, its drainage
basin reaches as far upstream as the Greensboro area (Fig. 1.1). The mainstem of the
river has been altered by the construction of several dams and water control structures.
In the coastal plain, the river is joined by two major tributaries, the Black and the
Northeast Cape Fear Rivers (Fig. 1.1). These 5th order blackwater streams drain
extensive riverine swamp forests and add organic color to the mainstem. The
watershed (about 9,149 square miles) is the most heavily industrialized in North
Carolina with 244 permitted wastewater discharges and (as of 2000) over 1.83 million
people residing in the basin (NCDENR 2005). Approximately 24% of the land use in the
watershed is devoted to agriculture and livestock production (NCDENR 2005), with
livestock production dominated by swine and poultry operations. Thus, the watershed
receives considerable point and non-point source loading of pollutants. However, the
estuary is a well-flushed system, with flushing tie ranging from 1 to 22 days with a
median flushing time of about seven days, much shorter than the other large N.C.
estuaries to the north (Ensign et al. 2004).
Water quality is monitored by boat at ten stations in the Cape Fear Estuary (from
Navassa to Southport) and one station in the Northeast Cape Fear Estuary (Table 1.1;
Fig. 1.1). Riverine stations sampled by boat include NC11, AC, DP, IC, and BBT (Table
1.1; Fig. 1.1). NC11 is located upstream of any major point source discharges in the
lower river and estuary system, and is considered to be representative of water quality
entering the lower system. BBT is located on the Black River between Thoroughfare
and the mainstem Cape Fear, and is influenced by both rivers. We consider B210 and
NCF117 to represent water quality entering the lower Black and Northeast Cape Fear
Rivers, respectively. Data has also been collected at stream and river stations
throughout the Cape Fear, Northeast Cape Fear, and Black River watersheds (Table
1.1; Fig. 1.1). Data collection at a station in the Atlantic Intracoastal Waterway was
initiated in February 1998 to obtain water quality information near the Southport
Wastewater Treatment Plant discharge.
1.2 Report Organization
This report contains two sections assessing LCFRP data. Section 2 presents an
overview of physical, chemical, and biological water quality data from the 36 individual
stations, and provides tables of raw data as well as figures showing spatial or temporal
2
trends. In Section 3 we analyze our data by sub-basin, compare our results with DWQ's
2006 Basinwide Plan, and make water quality ratings for dissolved oxygen, turbidity,
chlorophyll a, metals, and fecal coliform bacterial abundance. We also utilize other
relevant parameters such as nutrient concentrations to aid in these assessments. This
section is designed so that residents of a particular sub-basin can see what the water
quality is like in his or her area based on LCFRP data collections.
The LCFRP has a website that contains maps and an extensive amount of past water
quality, benthos, and fisheries data gathered by the Program available at:
www.uncwil.edu/cmsr/aquaticecology/lcfrp/
1.3 References Cited
Ensign, S.H., J.N. Halls and M.A. Mallin. 2004. Application of digital bathymetry data in
an analysis of flushing times of two North Carolina estuaries. Computers and
Geosciences 30:501-511.
NCDENR. 2005. Cape Fear River Basinwide Water Quality Plan. North Carolina
Department of Environment and Natural Resources, Division of Water
Quality/Planning, Raleigh, NC, 27699-1617.
3
Table 1.1. Description of sampling locations in the Cape Fear Watershed, 2006,
including UNCW designation and NCDWQ station designation number.
________________________________________________________________
UNCW St. DWQ No.
Location
________________________________________________________________
High order river and estuary stations
NC11
GPS
B8360000
At NC 11 bridge on Cape Fear River (CFR)
N 34.39663
W 78.26785
LVC2
GPS
B8441000
on Livingston Creek near Acme
N 34.33530
W 78.2011
AC
GPS
B8450000
5 km downstream from International Paper on CFR
N 34.35547
W 78.17942
DP
GPS
B8460000
At Dupont Intake above Black River
N 34.33595
W 78.05337
IC
GPS
B9030000
Cluster of dischargers upstream of Indian Cr. on CFR
N 34.30207
W 78.01372
B210
GPS
B9000000
Black River at Highway 210 bridge
N 34.43138
W 78.14462
BBT
GPS
none
Black River between Thoroughfare and Cape Fear River
N 34.35092
W 78.04857
NCF117
GPS
B9580000
Northeast Cape Fear River at Highway 117, Castle Hayne
N 34.36342
W 77.89678
NCF6
GPS
B9670000
Northeast Cape Fear River near GE dock
N 34.31710
W 77.95383
NAV
GPS
B9050000
Railroad bridge over Cape Fear River at Navassa
N 34.25943
W 77.98767
HB
GPS
B9050100
Cape Fear River at Horseshoe Bend
N 34.24372
W 77.96980
BRR
GPS
B9790000
Brunswick River near new boat ramp in Belville
N 34.22138
W 77.97868
4
M61
GPS
B9750000
Channel Marker 61, downtown at N.C. State Port
N 34.19377
W 77.95725
M54
GPS
B7950000
Channel Marker 54, 5 km downstream of Wilmington
N 34.13933
W 77.94595
M42
GPS
B9845100
Channel Marker 42 near Keg Island
N 34.09017
W 77.93355
M35
GPS
B9850100
Channel Marker 35 near Olde Brunswick Towne
N 34.03408
W 77.93943
M23
GPS
B9910000
Channel Marker 23 near CP&L intake canal
N 33.94560
W 77.96958
M18
GPS
B9921000
Channel Marker 18 near Southport
N 33.91297
W 78.01697
SPD
B9980000 1000 ft W of Southport WWT plant discharge on ICW
GPS
N 33.91708
W 78.03717
________________________________________________________________
Tributary stations collected from land
________________________________________________________________
SR
GPS
B8470000
South River at US 13, below Dunn runoff
N 35.15600
W 78.64013
GCO
GPS
B8604000
Great Coharie Creek at SR 1214
N 34.91857
W 78.38873
LCO
GPS
B8610001
Little Coharie Creek at SR 1207
N 34.83473
W 78.37087
6RC
GPS
B8740000
Six Runs Creek at SR 1003 (Lisbon Rd.)
N 34.79357
W 78.31192
BRN
GPS
B8340050
Browns Creek at NC 87
N 34.61360
W 78.58462
HAM
GPS
B8340200
Hammonds Creek at SR 1704
N 34.56853
W 78.55147
COL
GPS
B8981000
Colly Creek at NC 53
N 34.46500
W 78.26553
5
ANC
GPS
B9490000
Angola Creek at NC 53
N 34.65705
W 77.73485
NC403
GPS
B9090000
Northeast Cape Fear below Mt. Olive Pickle at NC403
N 35.17838
W 77.98028
PB
GPS
B9130000
Panther Branch below Cates Pickle
N 35.13445
W 78.13630
GS
GPS
B9191000
Goshen Swamp at NC 11
N 35.02923
W 77.85143
SAR
GPS
B9191500
Northeast Cape Fear River near Sarecta
N 34.97970
W 77.86251
LRC
GPS
B9460000
Little Rockfish Creek at NC 11
N 34.72247
W 77.98145
ROC
GPS
B9430000
Rockfish Creek at US 117
N 34.71689
W 77.97961
BCRR
GPS
B9500000
Burgaw Canal at Wright St., above WWTP
N 34.56334
W 77.93481
BC117
GPS
B9520000
Burgaw Canal at US 117, below WWTP
N 34.56391
W 77.92210
SC-CH
GPS
Smith Creek at Castle Hayne Rd.
N 34.25897
W 77.93872
6
Figure 1.1 Map of the Lower Cape Fear River system and the LCFRP sampling stations.
7
2.0 - Physical, Chemical, and Biological Characteristics of the
Lower Cape Fear River and Estuary
Michael A. Mallin and Matthew R. McIver
Aquatic Ecology Laboratory
Center for Marine Science
University of North Carolina Wilmington
2.1 Introduction
This section of the report includes a discussion of the physical, chemical, and biological
water quality parameters, concentrating on the January-December 2006 Lower Cape
Fear River Program monitoring period. These parameters are interdependent and
define the overall condition of the river. Physical parameters measured during this
study included water temperature, dissolved oxygen, field turbidity and laboratory
turbidity, total suspended solids (TSS), salinity, conductivity, pH and light attenuation.
The chemical makeup of the Cape Fear River was investigated by measuring the
magnitude and composition of nitrogen and phosphorus in the water, as well as
concentrations of United States Environmental Protection Agency (US EPA) priority
pollutant metals. Three biological parameters including fecal coliform bacteria,
chlorophyll a and biochemical oxygen demand were examined.
2.2 Materials and Methods
All samples and field parameters collected for the estuarine stations of the Cape Fear
River (NAV down through M18) were gathered on an ebb tide. This was done so that
the data better represented the river water flowing downstream through the system
rather than the tidal influx of coastal ocean water. Sample collection and analyses were
conducted according to the procedures in the Lower Cape Fear River Program Quality
Assurance/Quality Control (QA/QC) manual. Technical Representatives from the
LCFRP Technical Committee and representatives from the NC Division of Water Quality
inspect UNCW laboratory procedures and periodically accompany field teams to verify
proper procedures are followed. We note that our previous Livingston Creek station
(LVC) has been discontinued and a new station sampled from the dock of the Wright
Chemical Company near Acme (LVC2) was put into operation in 2005.
Physical Parameters
Water Temperature, pH, Dissolved Oxygen, Turbidity, Salinity, Conductivity
Field parameters were measured at each site using a YSI 6920 (or 6820) multiparameter water quality sonde displayed on a YSI 650 MDS. Each parameter is
measured with individual probes on the sonde. At stations sampled by boat (see Table
1.1) physical parameters were measured at 0.1 m, the middle of the water column, and
at the bottom (up to 12 m). Occasionally, high flow prohibited the sonde from reaching
8
the actual bottom and measurements were taken as deep as possible. At the
terrestrially sampled stations the physical parameters were measured at a depth of 0.1
m. Our laboratory at the UNCW CMS is State-certified by the N.C. Division of Water
Quality to perform field parameter measurements.
Chemical Parameters
Nutrients
All nutrient analyses were performed at the UNCW Center for Marine Science (CMS) for
samples collected prior to January 1996. A local State-certified analytical laboratory
was contracted to conduct all subsequent analyses except for orthophosphate, which is
performed at CMS. The following methods detail the techniques used by CMS
personnel for orthophosphate analysis.
Orthophosphate (PO4-3)
Water samples were collected ca. 0.1 m below the surface in triplicate in amber 125 mL
Nalgene plastic bottles and placed on ice. In the laboratory 50 mL of each triplicate was
filtered through separate1.0 micron pre-combusted glass fiber filters, which were frozen
and later analyzed for chlorophyll a. The triplicate filtrates were pooled in a glass flask,
mixed thoroughly, and approximately 100 mL was poured into a 125 mL plastic bottle to
be analyzed for orthophosphate. Samples were frozen until analysis.
Orthophosphate analyses were performed in duplicate using an approved US EPA
method for the Bran-Lubbe AutoAnalyzer (Method 365.5). In this technique the
orthophosphate in each sample reacts with ammonium molybdate and anitmony
potassium tartrate in an acidic medium (sulfuric acid) to form an anitmony-phosphomolybdate complex. The complex is then reacted with ascorbic acid and forms a deep
blue color. The intensity of the color is measured at a wavelength of 880 nm by a
colorimeter and displayed on a chart recorder. Standards and spiked samples were
analyzed for quality assurance.
Biological Parameters
Fecal Coliform Bacteria
Fecal coliform bacteria were analyzed at a State-certified laboratory contracted by the
LCFRP. Samples were collected approximately 0.1 m below the surface in sterile
plastic bottles provided by the contract laboratory and placed on ice for no more than six
hours before analysis.
9
Chlorophyll a
The analytical method used to measure chlorophyll a is described in Welschmeyer
(1994) and US EPA (1997) and was performed by CMS personnel. Chlorophyll a
concentrations were determined directly from the 1.0 micron filters used for filtering
samples for orthophosphate analysis. All filters were wrapped individually in foil, placed
in airtight containers and stored in the freezer. During analysis each filter is immersed
in 10 mL of 90% acetone for 24 hours, which extracts the chlorophyll a into solution.
Additionally, filters from samples taken at M61, M18, BC117 and BCRR are ground
during the extraction process. Chlorophyll a concentration of each solution is measured
on a Turner 10-AU fluorometer. The fluorometer uses an optimal combination of
excitation and emission bandwidth filters which reduces the errors inherent in the
acidification technique. Our laboratory at the CMS is State-certified by the N.C. Division
of Water Quality for the analysis of chlorophyll a.
Biochemical Oxygen Demand (BOD)
Five sites were originally chosen for BOD analysis. One site was located at NC11,
upstream of International Paper, and a second site was at AC, about 3 miles
downstream of International Paper (Fig.1.1). Two sites were located in blackwater
rivers (NCF117 and B210) and one site (BBT) was situated in an area influenced by
both the mainstem Cape Fear River and the Black River. For the sampling period May
2000-April 2004 additional BOD data were collected at stream stations 6RC, LCO,
GCO, BRN, HAM and COL in the Cape Fear and Black River watersheds. In May 2004
those stations were dropped and sampling commenced at ANC, SAR, GS, N403, ROC
and BC117 in the Northeast Cape Fear River watershed. The procedure used for BOD
analysis was Method 5210 in Standard Methods (APHA 1995). Samples were analyzed
for both 5-day and 20-day BOD. During the analytical period, samples were kept in
airtight bottles and placed in an incubator at 20o C. All experiments were initiated within
6 hours of sample collection. Samples were analyzed in duplicate. Dissolved oxygen
measurements were made using a YSI Model 57 meter that was air-calibrated. No
adjustments were made for pH since most samples exhibited pH values within or very
close to the desired 6.5-7.5 range (pH is monitored during the analysis as well).
Several sites have naturally low pH and there was no adjustment for these samples
because it would alter the natural water chemistry and affect true BOD.
2.3 Results and Discussion
This section includes results from monitoring of the physical, biological, and chemical
parameters at all stations for the time period January-December 2006. Discussion of
the data focuses mainly on the river channel stations, but poor water quality conditions
at stream stations will also be discussed. The contributions of the two large blackwater
tributaries, the Northeast Cape Fear River and the Black River, are represented by
conditions at NCF117 and B210, respectively. The Cape Fear Region did not
experience any significant hurricane activity during this monitoring period (after major
10
hurricanes in 1996, 1998, and 1999). Therefore this report reflects low to medium flow
conditions for the Cape Fear River and Estuary.
Physical Parameters
Water temperature
Water temperatures at all stations ranged from 4.6 to 31.7 oC and individual station
annual averages ranged from 16.2 to 20.9oC (Table 2.1). Highest temperatures
occurred during July and August and lowest temperatures during February. Stream
stations were generally cooler than river stations, most likely because of shading and
lower nighttime air temperatures affecting the shallower waters.
Salinity
Salinity at the estuarine stations ranged from 0.0 to 33.2 practical salinity units (psu)
and station annual means ranged from 0.9 to 24.1 psu (Table 2.2). Lowest salinities
occurred in September and highest salinities occurred in November. Two stream
stations, NC403 and PB, had occasional oligohaline conditions due to discharges from
pickle production facilities. Annual mean salinity for 2006 was equivalent to that of the
ten-year average for 1996-2005 for all stations, and slightly lower at the lower estuarine
stations (Figure 2.1).
Conductivity
Conductivity at estuarine stations ranged from 0.08 to 50.60 mS/cm and from 0.0 to
3.33 mS/cm at the freshwater stations (Table 2.3). Temporal conductivity patterns
followed those of salinity. Dissolved ionic compounds increase the conductance of
water, therefore, conductance increases and decreases with salinity, often reflecting
river flow conditions due to rainfall. Conductivity may also reveal point source pollution
sources, as is seen at BC117, which is below a municipal wastewater discharge.
Stations PB and NC403 are below an industrial discharge, and often have elevated
conductivity.
pH
pH values ranged from 3.8 to 8.1 and station annual medians ranged from 3.9 to 7.9
(Table 2.4). pH was typically lowest upstream due to acidic swamp water inputs and
highest downstream as alkaline seawater mixes with the river water. Low pH values at
COL predominate because of naturally acidic blackwater inputs.
11
Dissolved Oxygen
Dissolved oxygen (DO) problems are a major water quality concern in the lower Cape
Fear River and its estuary, and several of the tributary streams (Mallin et al. 1999; 2000;
2001a; 2001b; 2002a; 2002b; 2003; 2004; 2005a; 2006). Surface concentrations in
2006 ranged from 0.4 to 12.8 mg/L and station annual means ranged from 4.0 to 9.2
mg/L (Table 2.5). Average annual DO levels at the river channel stations for 2006 were
very similar to the average for 1996-2005 (Figure 2.2). Dissolved oxygen levels were
lowest during the summer (Table 2.5), often falling below the state standard of 5.0 mg/L
at several river and upper estuary stations. Working synergistically to lower oxygen
levels are two factors: lower oxygen carrying capacity in warmer water and increased
bacterial respiration (or biochemical oxygen demand, BOD), due to higher temperatures
in summer. Unlike other large North Carolina estuaries (the Neuse, Pamlico and New
River) the Cape Fear estuary rarely suffers from dissolved oxygen stratification. This is
because despite salinity stratification the oxygen remains well mixed due to strong
estuarine gravitational circulation and high freshwater inputs (Lin et al. 2006). Thus,
hypoxia in the Cape Fear is present throughout the water column.
There is a dissolved oxygen sag in the main river channel that begins at DP below a
paper mill discharge and persists into the mesohaline portion of the estuary (Fig. 2.2).
Mean oxygen levels were highest at the upper river stations NC11 and AC and in the
middle to lower estuary at stations M23 and M18. Lowest mainstem mean 2006 DO
levels occurred at the lower river and upper estuary stations NAV, HB, BRR and M61
(6.7-6.8 mg/L). Discharge of high BOD waste from the paper/pulp mill just above the
AC station (Mallin et al. 2003), as well as inflow of blackwater from the Northeast Cape
Fear and Black Rivers, help to diminish oxygen in the upper estuary. As the water
reaches the lower estuary higher algal productivity, mixing and ocean dilution help
alleviate oxygen problems.
The Northeast Cape Fear and Black Rivers generally have lower DO levels than the
mainstem Cape Fear River (NCF117 2006 mean = 6.1, NCF6 = 6.6, B210 2006 mean =
7.0). These rivers are classified as blackwater systems because of their tea colored
water. As the water passes through swamps en route to the river channel, tannins from
decaying vegetation leach into the water, resulting in the observed color. Decaying
vegetation on the swamp floor has an elevated biochemical oxygen demand and usurps
oxygen from the water, leading to naturally low dissolved oxygen levels. Runoff from
concentrated animal feeding operations (CAFOs) may also contribute to chronic low
dissolved oxygen levels in these blackwater rivers (Mallin et al. 1998; 1999; 2006; Mallin
2000). The Northeast Cape Fear River in general seems to be more oxygen stressed
than the Black River; in 2006 NCF117 had DO concentrations below 4.0 mg/L 33% of
the time sampled, while during that same period B210 had DO below 4.0 mg/L 0% of
the occasions sampled (Table 2.5)
Several stream stations were severely stressed in terms of low dissolved oxygen during
the year 2006. ANC had DO levels below 4.0 mg/L 25% of the occasions sampled,
12
NC403 33%, GS 50% and SR 33% (Table 2.5). Some of this can be attributed to low
water conditions and some potentially to CAFO runoff; however point-source discharges
also likely contribute to low dissolved oxygen levels at NC403 and possibly SR,
especially via nutrient loading (Mallin et al. 2001a; 2002a; 2004). Smith Creek had DO
levels below 5.0 mg/L 36% of the time. Hypoxia is thus a widespread problem, with
47% of the sites impacted in 2006.
Field Turbidity
Field turbidity levels ranged from 0 to 78 nephelometric turbidity units (NTU) and station
annual means ranged from 2 to 18 NTU (Table 2.6). Annual mean turbidity levels for
2006 were considerably lower than the long-term average (Fig. 2.3) probably a result of
generally low rainfall and a lack of major storm activity. Highest mean turbidities were
at NAV (18 NTU) followed by the upper river sites N11, AC and DP (14-15 NTU) with
turbidities gradually decreases downstream through the estuary (Figure 2.3). Turbidity
was lower in the blackwater tributaries (Northeast Cape Fear River and Black River)
than in the mainstem river.
Note: In addition to the laboratory-analyzed turbidity, the LCFRP uses nephelometers
designed for field use, which allows us to acquire in situ turbidity from a natural
situation. North Carolina regulatory agencies are required to use turbidity values from
water samples removed from the natural system, put on ice until arrival at a Statecertified laboratory, and analyzed using laboratory nephelometers. Standard Methods
notes that transport of samples and temperature change alters true turbidity readings.
Our analysis of samples using both methods shows that lab turbidity is nearly always
lower than field turbidity; thus we do not discuss lab turbidity in this report.
Total Suspended Solids
Total suspended solid (TSS) values system wide ranged from 0 to 71 mg/L with station
annual means from 2 to 20 mg/L (Table 2.7). The overall highest values were in the
ICW at Station SPD. For the river channel stations TSS was highest in mid-estuary at
M54, next in the upper estuary at NAV, and somewhat lower in the lower estuary. In the
stream stations TSS was generally low, except for BC117. Although total suspended
solids (TSS) and turbidity both quantify suspended material in the water column, they do
not always go hand in hand. High TSS does not mean high turbidity and vice versa.
This anomaly may be explained by the fact that fine clay particles are effective at
dispersing light and causing high turbidity readings, while not resulting in high TSS. On
the other hand, large organic or inorganic particles may be less effective at dispersing
light, yet their greater mass results in high TSS levels.
13
Light Attenuation
The attenuation of solar irradiance through the water column is measured by a
logarithmic function (k) per meter. The higher this light attenuation coefficient is the
more strongly light is attenuated (through absorbance or reflection) in the water column.
River and estuary light attenuation coefficients ranged from 1.27 to 6.72/m and station
annual means ranged from 1.70 at M18 to 4.00 /m at NCF6 (Table 2.8).
High light attenuation did not always coincide with high turbidity. Blackwater, though
low in turbidity, will attenuate light through absorption of solar irradiance. At NCF6 and
BBT, blackwater stations with moderate turbidity levels, light attenuation was high.
Compared to other North Carolina estuaries the Cape Fear has high average light
attenuation. The high average light attenuation is a major reason why phytoplankton
production in the major rivers and the estuary of the LCFR is generally low. Whether
caused by turbidity or water color this attenuation tends to limit light availability to the
phytoplankton (Mallin et al. 1997; 1999; 2004).
Chemical Parameters – Nutrients
Total Nitrogen
Total nitrogen (TN) is calculated from TKN (see below) plus nitrate; it is not analyzed in
the laboratory. TN ranged from 190 to 12,780 µg/L and station annual means ranged
from 567 to 4,533 µg/L (Table 2.9). Mean total nitrogen in 2006 was equivalent to the
ten-year mean at some channel stations and higher than the mean in the lower main
river, the lower estuary, and the two major blackwater tributaries (Figure 2.4). Previous
research (Mallin et al. 1999) has shown a positive correlation between river flow and TN
in the Cape Fear system. Total nitrogen concentrations remained fairly constant down
the river and declined from mid-estuary into the lower estuary, most likely reflecting
uptake of nitrogen into the food chain through algal productivity and subsequent grazing
by planktivores as well as through dilution and marsh denitrfication. The blackwater
rivers maintained TN concentrations equal to or somewhat lower than those found in the
mainstem Cape Fear River. One stream station, BC117, had a very high mean of 4,533
µg/L, likely from the upstream Town of Burgaw wastewater discharge. ANC, ROC,
6RCand SAR also had comparatively high TN values among the stream stations.
Temporal patterns for TN were not evident.
Nitrate+Nitrite
Nitrate+nitrite (henceforth referred to as nitrate) is the main species of inorganic
nitrogen in the Lower Cape Fear River. Concentrations system wide ranged from 5
(detection limit) to 11,610 µg/L and station annual means ranged from 86 to 2,182 µg/L
14
(Table 2.10). The highest riverine nitrate levels were at AC (545 µg/L) and NC11 (490
µg/L) indicating that much of this nutrient is imported from upstream. Moving
downstream, nitrate levels decrease most likely as a result of uptake by primary
producers, microbial denitrification in riparian marshes and tidal dilution. Despite this,
the rapid flushing of the estuary (Ensign et al. 2004) permits sufficient nitrate to enter
the coastal ocean in the plume and contribute to offshore productivity (Mallin et al.
2005b). Nitrate can limit phytoplankton production in the lower estuary in summer
(Mallin et al. 1999). The blackwater rivers carried low loads of nitrate compared to the
mainstem Cape Fear stations; i.e. the Northeast Cape Fear River (NCF117 mean = 180
µg/L) and the Black River (B210 = 187 µg/L). No clear temporal pattern was observable
for nitrate.
Several stream stations showed high levels of nitrate on occasion including SAR,
NC403, PB, BC117, ROC, 6RC and LCO. NC403 and PB are downstream of industrial
wastewater discharges and SAR, ROC and 6RC primarily receive non-point agricultural
or animal waste drainage. BC117 frequently showed high nitrate levels. The Town of
Burgaw wastewater plant, upstream of BC117, has no nitrate discharge limits. Over the
past several years a considerable number of experiments have been carried out by
UNCW researchers to assess the effects of nutrient additions to water collected from
blackwater streams and rivers (i.e. the Black and Northeast Cape Fear Rivers, and
Colly and Great Coharie Creeks). These experiments have collectively found that
additions of nitrogen (as either nitrate, ammonium, or urea) significantly stimulate
phytoplankton production and BOD increases. Critical levels of these nutrients were in
the range of 0.2 to 0.5 mg/L as N (Mallin et al. 1998; Mallin et al. 2001a; Mallin et al.
2002a, Mallin et al. 2004). Thus, we conservatively consider nitrate concentrations
exceeding 0.5 mg/L as N in Cape Fear watershed streams to be potentially problematic
to the streams environmental health.
Ammonium
Ammonium concentrations ranged from 5 (detection limit) to 6,510 µg/L and station
annual means ranged from 18 to 794 µg/L (Table 2.11). River areas with the highest
mean ammonium levels this monitoring period included AC, which is below a pulp mill
discharge, and DP, located downstream of AC. Ocean dilution and biological uptake
accounts for decreasing levels in the lower estuary. At the stream stations, areas with
periodic high levels of ammonium include LVC2, ANC, SAR, NC403, BRN, 6RC and
PB. BC117 had very high concentrations in February and March (1,970 and 6,510 µg/L,
respectively) – this station lies downstream of the Burgaw wastewater treatment plant.
Total Kjeldahl Nitrogen
Total Kjeldahl Nitrogen (TKN) is a measure of the total concentration of organic nitrogen
plus ammonium. TKN ranged from 190 to 11,290 µg/L and station annual means
15
ranged from 483 to 2,352 µg/L (Table 2.12). TKN concentration drops down through
the estuary, likely due to ocean dilution and food chain uptake of nitrogen.
Total Phosphorus
Total phosphorus (TP) concentrations ranged from 10 (detection limit) to 2,810 µg/L and
station annual means ranged from 49 to 788 µg/L (Table 2.13). Mean TP for 2006 was
lower than the ten-year mean from the upper river to mid-estuary, and higher than the
mean at the lower estuary and the major blackwater tributaries (Figure 2.5). In the river
TP is highest at the upper riverine channel stations and declines downstream into the
estuary. Some of this decline is attributable to the settling of phosphorus-bearing
suspended sediments, yet incorporation of phosphorus into the food chain is also
responsible. A temporal pattern of higher summer TP is a result of increasing
orthophosphate during the summer.
The experiments discussed above in the nitrate subsection also involved additions of
phosphorus, either as inorganic orthophosphate or a combination of inorganic plus
organic P. The experiments showed that additions of P exceeding 0.5 mg/L led to
significant increases in bacterial counts, as well as significant increases in BOD over
control. Thus, we consider concentrations of phosphorus above 0.5 to be potentially
problematic to blackwater streams. Streams periodically exceeding this critical
concentration included GS, NC403, GCO and BC117. Some of these stations (BC117,
NC403) are downstream of industrial or wastewater discharges, while GS and GCO are
in non-point agricultural areas.
Orthophosphate
Orthophosphate ranged from 0 to 1,860 µg/L and station annual means ranged from 11
to 568 µg/L (Table 2.14). Much of the orthophosphate load is imported into the Lower
Cape Fear system from upstream areas, as NC11 typically has the highest levels. The
Northeast Cape Fear River had higher orthophosphate levels than the Black River.
Orthophosphate can bind to suspended materials and is transported downstream via
particle attachment; thus high levels of turbidity at the uppermost river stations may be
an important factor in the high orthophosphate levels. Turbidity declines toward the
estuary because of settling, and orthophosphate concentration also declines. In the
estuary, primary productivity helps reduce orthophosphate concentrations by
assimilation into biomass. Orthophosphate levels typically reach maximum
concentrations during summertime, when anoxic sediment releases bound phosphorus.
Also, in the Cape Fear Estuary, summer algal productivity is limited by nitrogen, thereby
allowing the accumulation of orthophosphate (Mallin et al. 1997; 1999). In spring,
productivity in the estuary is usually limited by phosphorus (Mallin et al. 1997; 1999).
The stream station BC117 had high orthophosphate levels while ANC, NC403, ROC
and GCO had moderate levels. BC117 and NC403 are strongly influenced by industrial
and municipal wastewater discharges, and ANC, ROC and GCO by agriculture/animal
waste runoff.
16
Chemical Parameters - EPA Priority Pollutant Metals
Aluminum levels in the Lower Cape Fear system were generally higher in the upper
estuary and decreased toward the lower estuary (Table 2.15). Stream stations were
generally low except COL, which is considered pristine, although acidic swamp water.
There is no North Carolina aquatic standard for aluminum.
Arsenic, cadmium, and chromium all maintained concentrations below detection limits at
all stations (except As had measurable levels at SAR in June) throughout the year
(Tables 2.16, 2.17, and 2.18). The As concentrations were all below the N.C. standard.
Copper concentrations exceeded the state tidal saltwater standard of 3 µg/L once at
estuarine station M18 (Table 2.19). The freshwater standard of 7 µg/L was exceeded
once at the Stream DP.
The LCFRP is an iron-rich system (Table 2.20). Stations SAR, LRC, 6RC and GCO
maintained average iron concentrations above the state standard of 1000 µg/L. Iron
concentrations generally decreased down-estuary.
Water-column concentrations of lead, mercury, and nickel were below the analytical
detection limit except once for lead at DP and once for nickel at COL; the peak at COL
did exceed the N.C. state standard (Tables 2.21, 2.22, 2.23).
Zinc concentrations exceeded the state standard once each at M18 and DP (Table
2.24).
Biological Parameters
Chlorophyll a
During this monitoring period chlorophyll a was generally low to moderate at the river
and estuarine stations (Table 2.25). System wide, chlorophyll a ranged from 0.1 to 36.5
µg/L and station annual means ranged from 0.7 –8.1 µg/L. Production of chlorophyll a
biomass is low to moderate in this system primarily because of light limitation by
turbidity in the mainstem and high organic color and low inorganic nutrients in the
blackwater rivers. Spatially, highest values are normally found in the mid-to-lower
estuary stations because light becomes more available downstream of the estuarine
turbidity maximum (Figure 2.11). Flushing time of the Cape Fear estuary is rapid,
ranging from 1-22 days with a median of 6.7 days (Ensign et al. 2004). This does not
allow for much settling of suspended materials, leading to light limitation of
phytoplankton production. Chlorophyll a production is extremely limited in the large
17
blackwater tributaries. Highest chlorophyll a concentrations were found during spring
and summer.
Substantial phytoplankton blooms occasionally occur at the stream stations (Table
2.25). These streams are generally shallow, so vertical mixing does not carry
phytoplankton cells down below the critical depth where respiration exceeds
photosynthesis. Thus, when flow conditions permit, elevated nutrient conditions (such
as are periodically found in these stream stations) can lead to algal blooms. In areas
where the forest canopy opens up large blooms can occur. When blooms occur in
blackwater stream stations they can become sources of BOD upon death and decay,
reducing further the low summer dissolved oxygen conditions common to these waters
(Mallin et al. 2001; 2002; 2004). Stream algal blooms in 2006 occurred at GS, PB, and
BCRR.
Biochemical Oxygen Demand
For the mainstem river, mean annual five-day biochemical oxygen demand (BOD5)
concentrations were highest at AC, on average about 19% higher than at NC11
suggesting influence from the pulp/paper mill inputs (Table 2.26). BOD was somewhat
lower during the winter.
From 2000 until April 2004 we performed a project aimed at assessing rural Black River
system stream contributions to BOD. In May 2004 we changed the stream sampling to
the Northeast Cape Fear River watershed. Results of BOD analyses from several
stream stations can be seen in Table 2.26. The data show generally greater BOD
concentrations at the Northeast Cape Fear Watershed streams than the Black River
Watershed streams. GS, BC117, LVC2 and N403 all showed large (> 3.3 mg/L)
individual BOD5 measurements during 2006. Stations N403, LVC2 and BC117 are
below point sources, but the other two sites are non-point runoff areas.
Fecal Coliform Bacteria
Fecal coliform (FC) bacterial counts ranged from 1 to >6,000 CFU/100 mL and station
annual geometric means ranged from 15 to 1,111 CFU/100 mL (Table 2.27). The state
human contact standard (200 CFU/100 mL) was exceeded at several mainstem sites
during July and September in 2006. FC counts in 2006 were lower in the upper estuary
compared with the ten-year average, but much higher than the long term average in
mid-estuary and the two major blackwater tributaries (Figure 2.6).
All stream stations surpassed the state standard for human contact of 200 CFU/100 mL
on at least one occasion and several were particularly problematic. During 2006 PB
exceeded the state standard 42% of the time, HAM 50%, BCRR 75%, BC117 and SAR
67%, LRC and ROC 33%, and ANC, GS, NC403, LVC2, SC-CH and BRN exceeded the
18
standard 25% of the time. BC117, NC403, LVC2 and PB are located below point
source discharges and the other sites are primarily influenced by non-point source
pollution. Overall, elevated fecal coliform counts are very problematic in this system,
with 57% of the stations impacted in 2006.
2.4 References Cited
APHA. 1995. Standard Methods for the Examination of Water and Wastewater, 19th ed.
American Public Health Association, Washington, D.C.
Ensign, S.H., J.N. Halls and M.A. Mallin. 2004. Application of digital bathymetry data in
an analysis of flushing times of two North Carolina estuaries. Computers and
Geosciences 30:501-511.
Lin, J. L. Xie, L.J. Pietrafesa, J. Shen, M.A. Mallin and M.J. Durako. 2006. Dissolved
oxygen stratification in two microtidal partially-mixed estuaries. Estuarine, Coastal
and Shelf Science. 70:423-437.
Mallin, M.A., L.B. Cahoon, M.R. McIver, D.C. Parsons and G.C. Shank. 1997. Nutrient
limitation and eutrophication potential in the Cape Fear and New River Estuaries.
Report No. 313. Water Resources Research Institute of the University of North
Carolina, Raleigh, N.C.
Mallin, M.A., L.B. Cahoon, D.C. Parsons and S.H. Ensign. 1998. Effect of organic and
inorganic nutrient loading on photosynthetic and heterotrophic plankton communities
in blackwater rivers. Report No. 315. Water Resources Research Institute of the
University of North Carolina, Raleigh, N.C.
Mallin, M.A., L.B. Cahoon, M.R. McIver, D.C. Parsons and G.C. Shank. 1999.
Alternation of factors limiting phytoplankton production in the Cape Fear Estuary.
Estuaries 22:985-996.
Mallin, M.A. 2000. Impacts of industrial-scale swine and poultry production on rivers and
estuaries. American Scientist 88:26-37.
Mallin, M.A., M.H. Posey, M.R. McIver, S.H. Ensign, T.D. Alphin, M.S. Williams, M.L.
Moser and J.F. Merritt. 2000. Environmental Assessment of the Lower Cape Fear
River System, 1999-2000. CMS Report No. 00-01, Center for Marine Science,
University of North Carolina at Wilmington, Wilmington, N.C.
Mallin, M.A., L.B. Cahoon, D.C. Parsons and S.H. Ensign. 2001a. Effect of nitrogen and
phosphorus loading on plankton in Coastal Plain blackwater streams. Journal of
Freshwater Ecology 16:455-466.
19
Mallin, M.A., M.H. Posey, T.E. Lankford, M.R. McIver, S.H. Ensign, T.D. Alphin, M.S.
Williams, M.L. Moser and J.F. Merritt. 2001b. Environmental Assessment of the
Lower Cape Fear River System, 2000-2001. CMS Report No. 01-01, Center for
Marine Science, University of North Carolina at Wilmington, Wilmington, N.C.
Mallin, M.A., L.B. Cahoon, M.R. McIver and S.H. Ensign. 2002a. Seeking sciencebased nutrient standards for coastal blackwater stream systems. Report No. 341.
Water Resources Research Institute of the University of North Carolina, Raleigh,
N.C.
Mallin, M.A., M.H. Posey, T.E. Lankford, M.R. McIver, H.A. CoVan, T.D. Alphin, M.S.
Williams and J.F. Merritt. 2002b. Environmental Assessment of the Lower Cape Fear
River System, 2001-2002. CMS Report No. 02-02, Center for Marine Science,
University of North Carolina at Wilmington, Wilmington, N.C.
Mallin, M.A., M.R. McIver, H.A. Wells, M.S. Williams, T.E. Lankford and J.F. Merritt.
2003. Environmental Assessment of the Lower Cape Fear River System, 2002-2003.
CMS Report No. 03-03, Center for Marine Science, University of North Carolina at
Wilmington, Wilmington, N.C.
Mallin, M.A., M.R. McIver, S.H. Ensign and L.B. Cahoon. 2004. Photosynthetic and
heterotrophic impacts of nutrient loading to blackwater streams. Ecological
Applications 14:823-838.
Mallin, M.A., M.R. McIver, T.D. Alphin, M.H. Posey and J.F. Merritt. 2005a.
Environmental Assessment of the Lower Cape Fear River System, 2003-2004. CMS
Report No. 05-02, Center for Marine Science, University of North Carolina at
Wilmington, Wilmington, N.C.
Mallin, M.A., L.B. Cahoon and M.J. Durako. 2005b. Contrasting food-web support bases
for adjoining river-influenced and non-river influenced continental shelf ecosystems.
Estuarine, Coastal and Shelf Science 62:55-62.
Mallin, M.A., M.R. McIver and J.F. Merritt. 2006. Environmental Assessment of the
Lower Cape Fear River System, 2005. CMS Report No. 06-02, Center for Marine
Science, University of North Carolina at Wilmington, Wilmington, N.C.
U.S. EPA 1997. Methods for the Determination of Chemical Substances in Marine
and Estuarine Environmental Matrices, 2nd Ed. EPA/600/R-97/072. National
Exposure Research Laboratory, Office of Research and Development, U.S.
Environmental Protection Agency, Cincinnati, Ohio.
Welschmeyer, N.A. 1994. Fluorometric analysis of chlorophyll a in the presence of
chlorophyll b and phaeopigments. Limnology and Oceanography 39:1985-1993.
20
21
HB
8.9
9.6
15.0
18.9
20.0
26.5
28.4
31.4
25.1
23.7
16.6
11.3
19.6
7.2
31.4
8.9
SAR
8.2
9.8
13.8
16.6
17.5
21.8
25.0
26.9
22.8
19.9
15.0
8.3
17.1
6.1
26.9
8.2
NAV
9.0
9.2
14.6
18.6
19.8
26.1
28.3
30.9
25.0
22.8
15.4
11.3
19.3
7.2
30.9
9.0
ANC
8.0
8.8
12.7
14.5
19.0
21.4
25.7
28.2
23.0
20.4
16.7
10.1
17.4
6.4
28.2
8.0
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
GS
7.5
9.1
11.3
14.6
18.0
21
25.2
25.8
22.9
19.3
15.4
8.6
16.6
6.2
25.8
7.5
BRR
9.1
9.1
14.5
18.4
20.2
26.2
28.6
31.3
25.1
23.8
16.3
11.4
19.5
7.3
31.3
9.1
NC403
8.7
9.3
13.1
15.7
18.1
21.5
26.4
26.8
23.0
21.2
14.9
9.3
17.3
6.2
26.8
8.7
M61
9.4
10.0
14.2
18.7
20.0
25.9
28.8
31.7
24.8
24.1
16.2
11.8
19.6
7.2
31.7
9.4
PB
8.9
10.2
14.7
18.8
19.0
20.6
27.1
26.1
22.8
21.1
16.5
10.4
18.0
5.8
27.1
8.9
M54
9.9
9.7
13.9
18.0
19.9
25.7
29.2
31.3
25.4
24.1
16.7
11.8
19.6
7.2
31.3
9.7
LRC
10.7
9.5
15.4
17.2
17.7
18.5
25.8
25.6
22.2
20.2
15.1
10.3
17.4
5.3
25.8
9.5
M42
10.1
9.4
13.3
17.9
19.6
25.4
28.8
31.1
25.4
24.1
17.1
12.1
19.5
7.1
31.1
9.4
ROC
10.5
9.1
14.4
16.9
17.3
20.0
25.8
25.6
22.8
18.9
14.8
9.0
17.1
5.6
25.8
9.0
M35
10.5
9.8
13.3
17.6
19.8
25.5
29.2
30.9
25.7
24.6
17.1
12.2
19.7
7.1
30.9
9.8
BC117
11.3
9.4
15.9
18.1
17.3
18.6
27.1
24.9
21.9
20.7
15.4
11.8
17.7
5.2
27.1
9.4
M23
10.9
9.5
15.5
17.2
19.8
25.2
28.9
30.5
26.6
24.7
17.1
12.8
19.9
6.9
30.5
9.5
BCRR
9.3
9.0
12.5
15.7
16.7
18.1
24.2
24.5
21.6
18.5
15.1
10.2
16.3
5.2
24.5
9.0
M18
11.3
9.3
15.4
16.5
19.8
24.9
28.8
30.0
26.8
24.7
17.7
12.8
19.8
6.8
30.0
9.3
SPD
11.6
8.8
17.7
17.2
21.1
25.6
30.3
30.5
28.2
24.0
17.3
12.5
20.4
7.1
30.5
8.8
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
6RC
11.2
6.0
17.5
14.5
17.4
22.7
26.1
23.6
22.8
18.3
9.3
9.6
16.6
6.2
26.1
6.0
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
LCO
10.8
5.8
17.7
14.9
17.5
22.6
25.5
23.6
22.2
18.6
9.5
8.2
16.4
6.3
25.5
5.8
NC11
9.4
8.3
15.2
18.8
19.4
26.6
27.5
30.2
25.3
23.3
14.4
10.4
19.1
7.2
30.2
8.3
Table 2.1 Water temperature (oC) for 2006 at the Lower Cape Fear River Program stations.
GCO
12.4
4.6
18.2
14.4
17.1
22.5
26.0
23.5
22.6
18.5
8.9
7.7
16.4
6.6
26.0
4.6
AC
9.6
8.6
15.6
19.1
19.3
26.2
27.5
30.3
25.2
23.3
14.6
10.4
19.1
7.1
30.3
8.6
SR
11.4
4.6
19.2
15.0
16.3
22.5
25.5
23.9
22.8
18.6
8.9
7.9
16.4
6.6
25.5
4.6
DP
9.8
8.6
16.3
18.5
19.6
25.9
27.6
30.9
25.4
22.6
14.1
10.6
19.2
7.1
30.9
8.6
BRN
12.6
6.7
19.8
15.5
17.1
22.4
26.1
23.8
22.9
18.6
10.5
8.7
17.1
6.1
26.1
6.7
BBT
9.7
8.9
6.4
18.7
19.5
25.4
27.1
31.0
24.4
22.1
13.9
10.3
18.1
7.8
31.0
6.4
HAM
12.2
6.4
18.9
14.6
16.3
21.3
25.8
22.6
22.1
17.3
9.2
8.2
16.2
6.0
25.8
6.4
IC
9.6
8.9
16.1
18.8
19.6
26.1
27.6
31.1
24.8
22.7
14.3
10.4
19.2
7.1
31.1
8.9
NCF6
10.0
9.7
15.4
18.9
20.4
25.6
27.5
31.2
24.0
23.4
15.8
11.6
19.5
6.8
31.2
9.7
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
NCF117
9.9
9.2
16.3
18.4
20.0
25.8
26.9
30.8
23.8
21.8
14.2
11.5
19.1
6.7
30.8
9.2
B210
9.9
9.1
16.2
17.4
17.4
24.0
26.4
28.9
23.8
19.6
13.7
10.4
18.1
6.4
28.9
9.1
COL
10.2
8.2
14.9
12.6
15.8
21.2
24.8
26.4
23.0
16.6
13.7
8.1
16.3
6.0
26.4
8.1
LVC2
10.8
9.2
18.2
12.6
17.8
23.0
26.5
26.7
24.2
19.8
13.3
11.1
17.8
6.1
26.7
9.2
11.7
15.3
21.9
22.8
23.6
29.8
30.6
24.2
23.2
15.8
11.5
20.9
6.3
30.6
11.5
SC-CH
22
2.1
2.4
7.5
0.0
5.0
0.0
max
min
0.0
0.0
DEC
0.9
2.6
1.4
NOV
1.4
2.0
0.1
OCT
mean
0.0
std dev
3.6
0.1
7.5
0.0
5.0
JUN
0.2
1.5
0.1
MAY
6.2
1.6
SEP
2.1
APR
AUG
0.1
MAR
1.2
0.1
0.1
0.2
FEB
HB
JUL
0.1
JAN
NAV
0.0
8.6
3.0
3.1
0.1
1.9
5.5
0.0
6.3
0.1
8.6
1.5
6.8
5.1
1.0
0.1
BRR
0.0
12.8
4.8
6.0
0.1
3.2
10.5
0.0
10.1
0.9
12.8
6.7
12.1
9.9
5.1
0.2
M61
0.1
14.3
5.1
7.4
0.1
9.9
11.1
0.4
12.3
1.6
14.3
7.5
13.2
11.0
6.3
1.3
M54
0.6
15.5
5.5
9.1
0.6
13.2
13.6
1.0
15.5
2.9
13.7
8.8
14.4
13.6
9.3
2.5
M42
1.7
20.8
6.9
12.1
2.1
20.8
15.4
1.7
18.8
4.2
15.5
10.4
18.7
18.1
15.2
4.2
M35
6.6
28.6
7.3
19.1
6.6
26.9
22.6
6.8
25.4
12.2
21.8
19.5
24.4
28.6
21.5
12.5
M23
Table 2.2 Salinity (psu) for 2006 at the Lower Cape Fear River Program estuarine stations.
9.3
33.2
7.6
22.2
14.0
33.2
24.0
9.3
28.7
12.9
24.8
21.2
28.6
29.3
27.2
13.6
M18
13.1
29.4
4.9
24.1
13.1
27.6
27.7
15.8
29.4
22.9
28.1
24.6
27.9
26.8
24.3
21.1
SPD
0.0
3.9
1.2
0.9
0.0
3.9
0.9
0.0
3.0
0.1
0.6
0.3
1.7
0.1
0.1
0.1
NCF6
23
HB
0.12
2.31
3.11
10.73
0.47
13.06
0.12
6.61
0.08
3.70
4.87
0.10
3.77
4.20
13.06
0.08
SAR
0.15
0.17
0.18
0.17
0.14
0.20
0.16
0.19
0.12
0.18
0.17
0.13
0.16
0.02
0.20
0.12
NAV
0.13
0.47
0.25
4.02
0.14
8.99
0.13
2.83
0.08
0.26
2.73
0.10
1.68
2.57
8.99
0.08
ANC
0.08
0.12
0.11
0.09
0.08
0.09
0.13
0.09
0.06
0.06
0.09
0.07
0.09
0.02
0.13
0.06
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
GS
0.16
0.17
0.19
0.18
0.15
0.20
0.20
0.24
0.13
0.18
0.18
0.13
0.17
0.03
0.24
0.13
BRR
0.13
1.95
8.99
11.91
2.77
14.77
0.13
11.12
0.09
9.74
3.52
0.10
5.43
5.23
14.77
0.09
NC403
0.35
0.37
0.46
0.60
0.27
0.65
0.22
0.28
0.17
0.31
0.29
0.20
0.35
0.14
0.65
0.17
M61
0.34
9.07
16.70
20.20
11.60
21.41
1.77
17.37
0.09
17.81
5.88
0.10
10.19
8.02
21.41
0.09
PB
0.79
1.33
1.35
3.33
1.41
0.93
2.23
1.45
0.39
3.15
1.04
0.90
1.52
0.88
3.33
0.39
M54
2.55
11.09
18.55
21.93
12.96
23.67
3.16
20.79
0.80
18.79
16.66
0.11
12.59
8.44
23.67
0.11
LRC
0.12
0.13
0.12
0.16
0.10
0.19
0.16
0.07
0.06
0.11
0.11
0.12
0.12
0.04
0.19
0.06
M42
4.59
15.33
22.54
23.74
15.09
22.74
5.40
25.60
1.89
22.56
21.84
1.16
15.20
9.00
25.60
1.16
ROC
0.13
0.14
0.14
0.12
0.09
0.13
0.15
0.09
0.07
0.14
0.12
0.10
0.12
0.02
0.15
0.07
M35
7.50
25.00
29.04
29.97
17.64
25.45
7.68
30.68
3.27
25.24
33.20
3.93
19.88
10.81
33.20
3.27
BC117
0.31
0.48
0.59
0.61
0.30
0.27
0.79
0.32
0.13
0.93
0.13
0.34
0.43
0.24
0.93
0.13
M23
20.67
34.44
44.24
38.31
30.73
34.66
20.57
40.00
11.90
35.80
41.90
11.57
30.40
10.92
44.24
11.57
BCRR
0.16
0.14
0.14
0.22
0.11
0.22
0.29
0.09
0.06
0.17
0.06
0.08
0.15
0.07
0.29
0.06
M18
22.64
42.54
45.17
44.33
33.67
38.99
21.35
42.18
15.89
37.87
50.60
23.11
34.86
10.85
50.60
15.89
SPD
33.70
38.50
41.67
43.23
38.62
44.93
36.44
45.58
26.01
43.08
42.87
21.70
38.03
7.23
45.58
21.70
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
6RC
0.13
0.12
0.12
0.12
0.09
0.13
0.13
0.12
0.07
0.12
0.13
0.11
0.12
0.02
0.13
0.07
LCO
0.09
0.09
0.09
0.08
0.10
0.07
0.06
0.09
0.06
0.09
0.10
0.08
0.08
0.01
0.10
0.06
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
GCO
0.13
0.14
0.16
0.17
0.10
0.22
0.12
0.18
0.09
0.15
0.15
0.10
0.14
0.04
0.22
0.09
NC11
0.11
0.12
0.13
0.15
0.11
0.14
0.13
0.12
0.09
0.13
0.13
0.11
0.12
0.01
0.15
0.09
Table 2.3 Specific Conductivity (mS/cm) for 2006 at the Lower Cape Fear River Program stations.
SR
0.10
0.09
0.09
0.09
0.07
0.09
0.08
0.13
0.09
0.10
0.10
0.08
0.09
0.02
0.13
0.07
AC
0.18
0.12
0.20
0.20
0.14
0.31
0.25
0.14
0.12
0.17
0.13
0.11
0.17
0.06
0.31
0.11
BRN
0.11
0.11
0.11
0.11
0.07
0.10
0.12
0.11
0.09
0.12
0.12
0.10
0.10
0.01
0.12
0.07
DP
0.17
0.14
0.16
0.21
0.14
0.22
0.17
0.18
0.13
0.18
0.16
0.12
0.17
0.03
0.22
0.12
HAM
0.13
0.12
0.14
0.15
0.07
0.15
0.16
0.15
0.04
0.18
0.17
0.12
0.13
0.04
0.18
0.04
BBT
0.10
0.14
0.16
0.20
0.11
0.15
0.09
0.17
0.06
0.14
0.16
0.08
0.13
0.04
0.20
0.06
IC
0.12
0.16
0.18
0.21
0.13
0.22
0.13
0.19
0.08
0.18
0.18
0.10
0.16
0.04
0.22
0.08
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
NCF6
0.11
0.18
0.19
3.15
0.58
1.16
0.11
5.67
0.05
1.67
7.01
0.09
1.66
2.28
7.01
0.05
NCF117
0.11
0.20
0.14
0.19
0.14
0.19
0.11
0.15
0.05
0.13
0.13
0.09
0.13
0.04
0.20
0.05
B210
0.09
0.15
0.08
0.10
0.07
0.10
0.07
0.09
0.06
0.09
0.09
0.07
0.09
0.02
0.15
0.06
COL
0.07
0.07
0.06
0.06
0.06
0.06
0.06
0.06
0.06
0.07
0.06
0.06
0.06
0.00
0.07
0.06
LVC2
0.07
0.13
0.10
0.11
0.10
0.12
0.09
0.10
0.06
0.11
0.11
0.08
0.10
0.02
0.13
0.06
SC-CH
0.00
0.57
0.98
11.62
2.58
2.02
0.43
11.19
0.06
9.02
6.21
0.09
3.73
4.33
11.62
0.00
24
HB
6.6
7.9
7.3
7.6
6.9
7.2
6.6
6.9
6.2
6.8
7.3
6.5
6.9
0.5
7.9
6.2
SAR
6.7
6.8
6.6
6.7
6.6
7.0
6.5
6.7
6.1
7.0
6.6
6.5
6.7
0.2
7.0
6.1
NAV
6.8
7.1
7.1
7.4
6.6
7.1
6.6
6.9
6.1
6.8
7.4
6.5
6.9
0.4
7.4
6.1
ANC
5.4
6.5
6.1
6.0
5.9
5.9
6.6
6.1
4.3
4.8
5.6
4.8
5.9
0.7
6.6
4.3
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
median
std dev
max
min
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
median
std dev
max
min
GS
6.7
6.5
6.4
6.4
6.4
6.3
6.4
6.4
6.2
6.6
6.5
6.5
6.4
0.1
6.7
6.2
BRR
6.8
7.8
7.2
7.4
7.1
7.1
7.1
6.9
6.2
6.9
7.8
6.8
7.1
0.4
7.8
6.2
NC403
6.6
6.5
6.4
6.4
6.3
6.3
6.2
6.2
6.0
6.7
6.4
6.4
6.4
0.2
6.7
6.0
M61
6.7
7.6
7.4
7.5
7.2
7.3
6.8
7.1
6.1
6.9
7.7
6.5
7.2
0.5
7.7
6.1
PB
6.7
6.6
6.6
6.5
6.6
6.5
6.8
6.6
6.3
6.9
6.7
6.5
6.6
0.1
6.9
6.3
M54
7.0
7.8
7.5
7.7
7.4
7.5
7.2
7.2
6.4
7.0
7.9
6.7
7.2
0.4
7.9
6.4
LRC
7.1
7.2
7.3
7.6
6.9
7.7
7.6
6.3
6.0
7.1
6.8
6.9
7.1
0.5
7.7
6.0
M42
7.2
7.9
7.7
7.8
7.5
7.5
7.3
7.5
6.7
7.3
7.9
7.1
7.5
0.3
7.9
6.7
ROC
6.9
7.0
7.0
7.1
6.6
7.1
6.9
6.5
6.0
7.2
6.6
6.7
6.9
0.3
7.2
6.0
M35
7.4
8.0
7.8
7.8
7.6
7.7
7.3
7.7
7.2
7.4
8.0
7.1
7.7
0.3
8.0
7.1
BC117
7.4
7.6
7.3
7.4
7.2
7.1
7.7
7.2
6.3
7.6
6.4
7.3
7.3
0.4
7.7
6.3
M23
7.8
8.0
8.1
7.9
7.9
8.0
7.6
7.9
7.3
7.7
8.0
7.6
7.9
0.2
8.1
7.3
BCRR
7.1
7.2
7.0
7.2
6.6
6.9
7.2
6.6
5.5
6.3
5.8
6.6
6.8
0.5
7.2
5.5
M18
7.9
8.0
8.1
7.9
7.9
8.0
7.7
7.9
7.5
7.7
8.0
7.8
7.9
0.2
8.1
7.5
SPD
7.8
7.5
7.8
7.5
7.6
7.7
7.6
7.6
7.3
7.4
7.8
7.6
7.6
0.2
7.8
7.3
Table 2.4 pH for 2006 at the Lower Cape Fear River Program stations.
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
median
std dev
max
min
6RC
6.9
6.7
6.9
6.5
6.4
6.6
7.0
6.9
5.7
6.5
6.2
6.1
6.6
0.4
7.0
5.7
LCO
6.4
6.4
6.6
6.5
6.3
6.5
6.4
6.8
4.8
6.2
6.2
5.6
6.4
0.5
6.8
4.8
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
median
std dev
max
min
GCO
6.4
6.4
6.6
6.5
6.2
6.6
6.4
6.7
5.7
6.2
6.2
6.0
6.4
0.3
6.7
5.7
NC11
7.0
6.7
7.0
7.2
6.7
6.6
6.8
6.7
6.4
6.7
6.6
6.7
6.7
0.2
7.2
6.4
SR
6.1
6.1
6.2
6.2
6.1
6.3
6.2
6.3
5.9
6.0
6.2
6.0
6.2
0.1
6.3
5.9
AC
7.0
6.9
7.1
7.3
6.8
7.1
7.1
6.8
6.5
6.8
6.9
6.7
6.9
0.2
7.3
6.5
BRN
6.7
6.7
6.9
6.8
6.3
6.9
7.0
6.7
5.9
6.6
6.6
6.3
6.7
0.3
7.0
5.9
DP
7.0
6.7
6.8
7.0
6.8
6.8
7.0
6.8
6.5
6.7
6.8
6.8
6.8
0.1
7.0
6.5
HAM
6.9
6.8
6.9
6.8
6.1
6.9
7.0
6.8
5.9
6.7
6.6
6.5
6.8
0.3
7.0
5.9
BBT
6.3
6.8
6.8
6.9
6.5
6.6
6.3
6.8
5.8
6.6
6.8
6.2
6.6
0.3
6.9
5.8
IC
6.6
6.9
6.9
7.0
6.7
6.8
6.7
6.7
6.0
6.7
6.9
6.5
6.7
0.3
7.0
6.0
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
median
std dev
max
min
NCF6
6.3
6.7
6.8
7.0
6.8
6.7
6.4
6.8
5.8
6.4
7.0
6.2
6.7
0.3
7.0
5.8
NCF117
6.1
6.5
6.6
6.9
6.2
6.8
6.3
6.4
5.7
6.5
6.0
5.8
6.4
0.4
6.9
5.7
B210
6.0
6.3
6.2
6.5
5.7
6.5
6.0
6.1
5.5
6.2
5.7
5.5
6.1
0.3
6.5
5.5
COL
3.9
3.9
3.9
4.0
3.9
4.2
3.9
4.0
4.0
3.9
4.0
3.8
3.9
0.1
4.2
3.8
LVC2
6.3
7.3
6.2
6.9
6.8
6.6
6.6
6.8
5.9
5.9
6.5
6.2
6.6
0.4
7.3
5.9
7.3
6.3
7.1
6.9
7.0
6.8
6.4
5.9
5.8
6.0
5.9
6.4
0.5
7.3
5.8
SC-CH
25
5.0
HB
10.2
10.4
8.2
8.3
6.2
4.9
4.9
4.0
4.0
4.9
7.6
7.5
6.8
2.2
10.4
4.0
SAR
8.8
9.8
8.7
7.9
6.5
7.0
4.1
5.1
4.2
6.1
6.3
9.3
7.0
1.9
9.8
4.1
5.0
NAV
10.4
11.3
8.2
8.0
6.2
4.5
4.9
3.9
3.9
5.3
7.5
7.6
6.8
2.3
11.3
3.9
ANC
8.8
9.7
7.3
6.9
6.6
4.6
1.3
1.8
0.8
4.3
5.6
7.1
5.4
2.8
9.7
0.8
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
GS
8.7
7.2
4.8
3.8
4.3
0.4
1.0
1.4
2.8
1.3
4.6
8.2
4.0
2.7
8.7
0.4
5.0
BRR
10.2
10.9
8.5
7.9
6.0
5.0
5.2
4.1
4.1
4.5
7.6
7.6
6.8
2.2
10.9
4.1
NC403
8.4
8.6
6.8
6.2
4.3
0.4
0.9
0.8
1.8
4.2
4.7
8.0
4.6
2.9
8.6
0.4
5.0
M61
9.6
10.1
8.4
8.2
6.4
6.1
4.2
4.4
3.3
4.5
7.7
7.2
6.7
2.1
10.1
3.3
PB
10.1
10.3
9.2
7.8
7.5
5.2
6.0
3.4
5.2
6.8
7.5
9.1
7.3
2.0
10.3
3.4
5.0
M54
9.7
10.7
8.8
8.2
6.8
6.3
4.7
4.7
3.8
4.6
7.4
7.4
6.9
2.1
10.7
3.8
LRC
11.2
11.4
10.2
11.1
8.6
9.1
8.7
6.2
5.9
8.0
9.3
10.3
9.2
1.7
11.4
5.9
5.0
M42
9.7
11.3
8.3
8.4
7.3
6.2
4.7
5.6
3.6
5.1
8.1
7.8
7.2
2.1
11.3
3.6
ROC
10.4
10.9
9.4
8.8
7.5
6.9
6.1
4.8
3.3
7.3
7.9
10.2
7.8
2.2
10.9
3.3
5.0
M35
9.8
10.6
8.9
8.5
7.3
6.6
5.4
5.9
4.1
5.3
8.0
8.1
7.4
1.9
10.6
4.1
BC117
10.5
10.9
5.0
12.8
7.7
6.3
7.2
5.5
6.3
5.6
8.3
9.5
8.0
2.4
12.8
5.0
6.0
M23
9.8
10.6
9.1
8.4
7.6
6.2
5.8
6.0
4.8
5.6
7.8
8.6
7.5
1.8
10.6
4.8
BCRR
10.6
10.5
8.6
6.2
7.2
5.5
2.3
5.7
6.1
5.5
8.2
9.7
7.2
2.3
10.6
2.3
6.0
M18
9.8
10.4
9.0
8.2
7.6
6.2
5.9
6.1
5.2
5.8
7.5
8.7
7.5
1.6
10.4
5.2
6.0
SPD
9.0
11.4
8.0
7.8
6.5
4.7
6.5
5.1
4.5
5.3
8.0
8.5
7.1
2.0
11.4
4.5
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
6.0
6RC
10.2
11.9
8.5
8.8
7.8
6.9
6.5
6.9
3.6
8.1
10.6
9.2
8.3
2.1
11.9
3.6
LCO
10.3
11.9
8.5
9.0
7.1
7.0
6.6
7.1
4.3
8.2
10.2
8.5
8.2
1.9
11.9
4.3
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
GCO
7.3
10.6
6.1
7.1
5.4
4.4
3.1
4.3
3.1
5.8
7.9
7.9
6.1
2.1
10.6
3.1
5.0
NC11
11.4
12.7
10.3
9.9
8.0
6.8
6.7
6.4
6.9
7.2
9.3
9.6
8.8
2.0
12.7
6.4
SR
7.6
10.1
5.4
6.6
5.2
4.2
2.5
0.9
0.6
1.1
10.4
6.5
5.1
3.2
10.4
0.6
AC
11.2
12.2
9.7
9.5
7.8
6.0
6.3
5.7
6.1
6.6
9.1
9.3
8.3
2.1
12.2
5.7
5.0
BRN
10.1
12.6
9.0
10.2
7.3
7.6
7.5
7.2
5.7
8.6
9.6
7.8
8.6
1.8
12.6
5.7
DP
11.0
11.8
8.8
7.9
7.6
4.8
5.8
4.6
5.7
5.3
9.0
9.1
7.6
2.3
11.8
4.6
5.0
HAM
9.9
12.4
8.0
8.2
8.9
5.6
5.7
6.0
7.1
6.2
7.4
7.6
7.8
1.9
12.4
5.6
BBT
10.0
11.5
8.8
7.8
5.9
4.5
4.1
4.6
3.7
5.2
9.0
7.2
6.9
2.5
11.5
3.7
IC
10.3
11.4
8.7
7.7
6.6
4.3
4.8
4.6
4.0
5.0
9.0
7.9
7.0
2.4
11.4
4.0
NCF117
JAN
9.0
10.9
FEB
MAR
8.2
7.5
APR
MAY
6.3
5.0
JUN
JUL
3.6
3.7
AUG
SEP
3.6
3.6
OCT
NOV
7.0
5.0
DEC
mean
6.1
2.3
std dev
max
10.9
3.6
min
NCF6
8.6
10.1
9.4
7.8
6.2
5.9
3.8
4.9
3.0
3.9
8.7
7.0
6.6
2.3
10.1
3.0
6.0
B210
10.1
10.7
7.8
7.8
6.9
5.6
4.4
4.8
4.7
6.6
7.5
7.3
7.0
1.9
10.7
4.4
Table 2.5 Dissolved Oxygen (mg/l) for 2006 at the Lower Cape Fear River Program stations. The NC State standard is listed above each station.
COL
8.7
9.7
7.3
8.1
7.3
6.0
4.3
5.8
3.7
6.6
6.6
7.5
6.8
1.6
9.7
3.7
LVC2
9.7
9.9
6.3
8.1
5.4
4.2
3.3
4.6
4.9
5.2
7.5
4.5
6.1
2.1
9.9
3.3
11.2
9.2
6.6
5.8
5.5
3.8
4.0
3.1
4.7
7.6
7.3
6.3
2.3
11.2
3.1
SC-CH
26
25
HB
12
15
7
19
11
14
12
9
12
10
11
15
12
3
19
7
50
SAR
2
4
5
10
4
4
6
9
6
4
7
3
5
2
10
2
25
NAV
11
12
8
22
19
22
18
46
14
20
11
16
18
9
46
8
50
ANC
4
5
8
10
8
6
6
3
3
4
10
4
6
2
10
3
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
50
GS
1
1
1
2
1
6
8
6
2
2
2
2
3
2
8
1
25
BRR
9
13
8
17
25
9
13
7
15
8
12
14
13
5
25
7
50
NC403
1
0
1
1
1
9
9
6
2
1
3
1
3
3
9
0
25
M61
21
12
8
10
14
5
9
5
18
5
10
15
11
5
21
5
50
PB
2
2
5
6
3
11
21
7
5
5
5
4
6
5
21
2
25
M54
18
14
7
12
8
7
11
6
29
5
7
34
13
9
34
5
50
LRC
4
2
5
6
15
4
5
17
17
3
18
10
9
6
18
2
25
M42
12
14
7
11
8
5
10
8
21
5
6
17
10
5
21
5
50
ROC
4
3
4
7
7
8
10
11
8
4
12
4
7
3
12
3
25
M35
9
8
7
12
7
4
9
5
13
5
6
15
8
3
15
4
50
BC117
7
7
42
9
10
23
11
15
19
9
26
5
15
10
42
5
25
M23
6
12
8
12
6
4
6
4
7
6
6
9
7
3
12
4
50
BCRR
6
6
16
13
15
27
10
13
13
8
19
9
13
6
27
6
25
M18
4
15
13
14
10
4
4
4
6
5
21
6
9
5
21
4
25
SPD
5
13
10
13
13
8
10
9
18
7
11
10
11
3
18
5
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
50
6RC
3
3
4
4
40
6
5
9
6
8
4
4
8
10
40
3
50
LCO
1
2
3
2
18
0
6
2
4
4
4
1
4
5
18
0
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
50
GCO
1
1
1
2
5
6
11
6
3
4
2
0
4
3
11
0
50
NC11
13
14
8
6
28
11
12
10
15
13
25
23
15
7
28
6
50
SR
0
1
1
2
6
3
1
18
4
5
2
8
4
5
18
0
50
AC
14
12
6
5
24
17
15
17
12
14
21
27
15
6
27
5
50
BRN
6
3
4
6
14
23
6
10
9
6
4
6
8
5
23
3
50
DP
15
8
4
8
28
17
19
8
13
13
11
22
14
7
28
4
50
HAM
9
5
4
5
27
12
8
5
15
5
5
5
9
6
27
4
50
BBT
4
6
4
5
10
11
6
7
3
10
9
6
7
3
11
3
50
IC
9
7
5
9
16
11
14
12
10
14
10
12
11
3
16
5
50
NCF117
JAN
5
7
FEB
MAR
5
3
APR
MAY
4
3
JUN
JUL
4
2
AUG
SEP
9
3
OCT
NOV
3
3
DEC
mean
4
std dev
2
9
max
min
2
50
NCF6
5
7
18
17
29
23
7
7
11
32
18
7
15
9
32
5
50
B210
2
5
3
2
5
3
2
3
4
4
3
3
3
1
5
2
50
COL
2
2
4
1
2
1
1
2
0
3
2
1
2
1
4
0
50
LVC2
4
3
5
5
9
5
5
78
3
7
10
3
11
20
78
3
9
13
17
15
15
7
10
8
19
29
11
14
6
29
7
50
SC-CH
Table 2.6 Field Turbidity (NTU) for 2006 at the Lower Cape Fear River Program stations. The NC State standard for Lab Turbidity is listed above each station.
27
HB
12
15
10
18
10
15
9
18
10
9
7
14
12
4
18
7
SAR
3
2
6
9
5
3
5
12
4
4
3
3
5
3
12
2
NAV
9
9
9
18
12
14
13
56
14
22
8
13
16
13
56
8
ANC
3
3
5
6
6
9
5
3
3
4
3
2
4
2
9
2
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
GS
2
1
2
3
3
16
10
11
3
4
2
2
5
5
16
1
BRR
9
9
14
15
12
14
7
15
9
7
8
12
11
3
15
7
NC403
1
0
2
5
3
10
6
6
2
4
2
1
4
3
10
0
M61
18
13
18
8
13
9
6
10
16
5
9
14
12
4
18
5
PB
2
4
7
7
10
8
9
9
4
10
4
2
6
3
10
2
M54
18
12
17
19
10
11
9
16
71
5
8
42
20
18
71
5
LRC
4
2
3
3
6
1
3
24
15
3
12
9
7
7
24
1
M42
14
17
19
12
10
8
8
23
16
8
6
18
13
5
23
6
ROC
5
2
4
8
11
6
3
13
6
3
11
5
6
3
13
2
M35
12
8
21
11
10
10
9
19
11
6
7
14
12
4
21
6
BC117
5
6
14
6
10
18
5
12
18
6
19
4
10
5
19
4
M23
7
13
36
12
15
8
13
22
7
8
8
10
13
8
36
7
BCRR
3
2
3
7
9
15
6
8
9
6
9
6
7
3
15
2
M18
7
28
18
15
16
12
11
28
15
7
19
12
16
7
28
7
SPD
7
26
55
15
24
15
27
44
45
14
20
20
26
14
55
7
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
6RC
4
3
5
2
30
3
3
8
3
6
2
4
6
7
30
2
LCO
3
3
4
0
22
1
7
2
2
3
2
1
4
6
22
0
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
GCO
2
1
4
0
6
6
13
6
3
4
2
1
4
3
13
0
NC11
10
8
11
8
26
7
13
8
9
5
12
21
12
6
26
5
Table 2.7 Total Suspended Solids (mg/L) 2006 at the Lower Cape Fear River Program stations.
SR
1
1
2
2
6
4
3
17
10
5
2
5
5
4
17
1
AC
12
8
8
6
22
6
24
14
9
6
10
25
13
7
25
6
BRN
10
4
5
4
14
13
3
10
11
2
2
4
7
4
14
2
DP
12
5
6
6
20
10
22
6
8
8
6
19
11
6
22
5
HAM
10
3
2
2
16
6
7
3
16
2
2
2
6
5
16
2
IC
8
6
8
12
20
7
12
4
9
10
6
11
9
4
20
4
NCF6
5
7
50
23
41
22
3
7
10
11
11
6
16
14
50
3
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
NCF117
2
3
5
3
4
3
4
2
6
3
2
2
3
1
6
2
B210
0
2
4
1
3
4
5
2
4
2
2
1
3
1
5
0
COL
0
1
5
2
2
3
2
3
2
2
2
0
2
1
5
0
LVC2
1
1
3
4
4
5
4
29
5
2
5
2
5
7
29
1
28
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
HB
2.92
3.52
2.88
3.61
3.41
3.33
3.28
0.28
3.61
2.88
NAV
2.88
2.68
2.97
3.64
2.89
4.07
3.19
0.50
4.07
2.68
2.94
0.43
3.60
2.23
3.26
3.60
2.23
2.69
BRR
2.86
2.98
2.97
0.91
4.50
1.78
2.01
3.14
1.78
3.50
M61
4.50
2.89
2.68
0.86
3.97
1.50
1.67
2.74
1.50
3.14
M54
3.97
3.05
2.23
0.45
2.66
1.43
2.40
3.56
2.91
0.64
3.56
1.90
1.43
2.60
M35
2.66
2.05
1.90
2.81
M42
3.36
1.86
0.34
2.31
1.40
2.31
1.40
1.73
M23
2.00
1.70
0.26
1.89
1.26
1.82
1.26
1.83
M18
1.89
2.00
0.49
2.91
1.27
1.78
2.91
1.27
2.15
SPD
1.99
1.90
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
2.37
0.49
3.54
2.03
2.35
NC11
2.18
2.16
2.03
2.10
3.54
2.22
2.56
0.44
3.32
2.05
2.57
2.20
3.32
AC
2.67
2.05
Table 2.8 Light Attenuation (k) 2006 at the Lower Cape Fear River Program stations.
Equipment problems resulted in data gaps.
2.84
0.57
3.63
1.90
2.83
3.15
3.63
DP
2.67
1.90
2.82
0.58
3.89
2.31
2.48
2.95
3.89
IC
2.45
2.31
4.00
1.56
6.72
2.24
3.26
4.64
6.72
NCF6
3.16
2.24
2.91
0.59
3.85
2.28
3.08
3.05
3.85
BBT
2.29
2.28
29
HB
860
880
1,420
1,210
1,200
1,190
1,200
1,030
1,060
590
1,760
1,740
1,178
327
1,760
590
SAR
1,580
1,730
1,210
1,380
990
1,280
2,340
1,340
1,360
440
1,530
2,260
1,453
491
2,340
440
NAV
1,000
1,180
1,300
1,520
1,080
1,170
780
1,760
1,390
560
2,480
1,840
1,338
493
2,480
560
ANC
1,500
1,340
1,310
880
1,620
1,550
1,820
1,700
1,800
1,420
1,810
2,300
1,588
335
2,300
880
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
GS
840
730
700
1,040
840
1,400
220
1,300
2,030
220
1,820
2,020
1,097
602
2,030
220
BRR
1,100
1,000
1,350
1,100
1,310
890
1,160
1,060
1,030
530
1,260
2,020
1,151
334
2,020
530
NC403
1,500
980
740
1,160
920
1,170
1,560
1,600
1,080
600
2,560
2,850
1,393
659
2,850
600
M61
1,520
950
860
1,090
1,120
900
1,330
1,120
1,560
470
1,430
1,710
1,172
339
1,710
470
PB
1,420
1,720
1,030
1,350
720
1,000
1,050
1,300
2,010
1,730
1,130
2,260
1,393
437
2,260
720
M54
1,690
1,320
810
1,120
1,060
950
1,420
1,020
1,370
420
1,410
1,530
1,177
337
1,690
420
LRC
1,170
620
560
820
790
1,020
990
1,070
1,410
1,120
2,280
1,910
1,147
486
2,280
560
M42
1,020
1,050
1,170
1,210
1,200
970
1,130
1,010
1,180
400
380
2,180
1,075
432
2,180
380
ROC
1,350
1,080
1,060
1,090
960
1,370
2,210
1,440
1,570
2,370
2,310
1,490
1,525
482
2,370
960
M35
1,000
810
440
760
1,130
810
1,200
660
820
390
320
2,060
867
447
2,060
320
BC117
1,180
3,460
11,540
12,780
1,500
5,110
7,030
1,760
1,750
1,980
3,370
2,940
4,533
3,776
12,780
1,180
M23
780
720
190
1,200
760
280
1,080
310
960
320
1,090
2,480
848
596
2,480
190
BCRR
910
770
790
980
600
3,940
1,390
650
970
1,230
2,300
2,360
1,408
948
3,940
600
M18
1,770
620
190
400
730
190
770
320
960
300
200
350
567
438
1,770
190
SPD
1,210
470
280
5,310
810
190
650
230
1,140
220
260
380
929
1,364
5,310
190
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
6RC
2,040
1,160
1,390
2,050
390
1,070
900
1,250
1,990
1,000
2,570
2,570
1,532
666
2,570
390
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
Table 2.9 Total Nitrogen (µg/l) 2006 at the Lower Cape Fear River Program stations.
LCO
1,680
1,400
1,000
1,520
1,640
1,150
1,300
1,030
1,570
720
1,610
1,760
1,365
312
1,760
720
NC11
1,060
1,030
1,190
1,310
1,080
1,430
1,570
770
1,100
960
1,840
2,520
1,322
456
2,520
770
GCO
1,370
1,160
1,010
9,500
1,030
1,170
750
1,640
1,000
280
1,250
350
1,709
2,378
9,500
280
AC
1,230
1,070
1,470
1,690
1,110
1,840
1,000
850
990
1,560
1,890
2,920
1,468
552
2,920
690
SR
740
760
590
1,290
1,030
930
1,220
1,900
1,500
230
2,060
1,860
1,176
546
2,060
230
DP
1,480
1,330
910
1,460
1,460
1,620
1,950
1,610
870
2,330
2,330
2,230
1,632
475
2,330
850
BRN
1,260
1,050
640
880
560
1,160
1,210
1,230
1,490
430
2,400
1,790
1,175
525
2,400
430
IC
1,580
1,090
1,040
1,400
1,350
1,440
1,500
1,370
1,090
690
2,280
2,340
1,431
458
2,340
870
HAM
1,340
1,120
780
660
1,200
730
1,050
790
1,480
260
1,200
2,200
1,068
471
2,200
260
NCF6
980
1,100
1,180
1,150
1,240
1,120
1,640
930
1,460
320
1,930
2,400
1,288
505
2,400
320
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
NCF117
1,060
1,390
790
1,300
1,340
780
1,670
900
1,320
270
320
1,380
1,043
422
1,670
270
B210
830
1,440
1,020
850
990
1,000
2,060
850
1,350
440
1,770
2,140
1,228
508
2,140
440
COL
1,780
920
1,260
1,180
1,030
1,340
1,620
1,100
1,200
220
2,200
2,100
1,329
518
2,200
220
LVC2
1,050
860
1,280
4,810
980
1,020
1,060
710
740
1,060
1,510
1,340
1,368
1,062
4,810
710
30
HB
110
130
440
420
270
160
410
330
60
390
260
340
277
127
440
60
SAR
510
520
40
210
60
300
190
140
60
240
130
260
222
153
520
40
NAV
300
200
460
450
290
240
410
270
90
360
380
340
316
103
460
90
ANC
190
80
13
370
80
100
100
13
13
10
210
10
99
105
370
10
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
GS
90
170
13
60
13
13
30
13
230
20
20
320
83
98
320
13
BRR
350
210
460
400
380
140
460
310
130
330
360
320
321
105
460
130
NC403
890
560
40
370
30
13
70
13
80
400
360
1250
340
379
1,250
13
M61
30
110
300
340
280
110
350
280
60
270
230
310
223
109
350
30
PB
770
600
13
90
160
70
20
13
710
530
230
960
347
330
960
13
M54
240
110
250
280
130
110
350
270
70
220
210
230
206
80
350
70
LRC
380
250
13
70
40
180
60
72
210
120
280
510
182
145
510
13
M42
40
120
240
280
220
80
290
170
80
200
180
280
182
82
290
40
ROC
420
330
80
160
70
250
1000
140
170
1370
310
290
383
380
1,370
70
M35
160
110
210
200
340
60
270
150
120
190
120
260
183
76
340
60
BC117
340
430
250
11610
330
3100
5720
360
650
1780
770
840
2,182
3,234
11,610
250
M23
30
70
13
130
110
13
190
80
160
120
90
280
107
74
280
13
BCRR
160
60
13
90
40
1930
80
50
70
30
200
60
232
515
1,930
13
M18
140
60
13
70
120
13
160
40
160
100
10
150
86
57
160
10
SPD
510
50
13
40
110
13
13
13
140
10
60
180
96
136
510
10
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
NC11
220
420
540
610
380
680
520
490
200
760
640
420
490
165
760
200
LCO
790
420
390
350
50
120
40
130
170
520
510
460
329
220
790
40
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
6RC
1,110
410
460
980
60
140
200
150
290
800
870
770
520
352
1,110
60
GCO
480
370
120
70
13
13
13
40
13
80
50
150
118
146
480
13
AC
250
420
540
620
410
720
490
430
190
1360
690
420
545
289
1,360
190
SR
90
60
30
30
13
13
50
13
13
30
60
60
39
24
90
13
DP
410
300
300
530
570
550
500
350
170
530
430
430
423
118
570
170
BRN
650
300
130
130
50
40
180
30
90
230
200
390
202
170
650
30
IC
510
300
430
470
420
460
380
390
90
490
480
340
397
110
510
90
HAM
410
370
130
50
130
30
70
90
180
60
10
300
153
130
410
10
NCF6
140
170
110
120
120
190
240
230
60
120
230
300
169
67
300
60
465
454
175
488
180
523
523
303
425
134
576
175
BBT
505
576
488
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
NCF117
80
360
180
270
220
130
180
150
120
70
120
280
180
84
360
70
B210
40
510
230
150
150
110
150
100
150
240
170
240
187
113
510
40
Table 2.10 Nitrate/Nitrite (µg/l) 2006 at the Lower Cape Fear River stations. The NC State standard (10.0 mg/L) only affects NC11 because of
its classification as a water supply.
COL
430
25
13
60
50
30
30
260
13
10
10
10
78
125
430
10
LVC2
440
110
70
3640
90
130
80
60
40
160
110
40
414
978
3,640
40
31
HB
60
60
20
130
130
120
50
20
40
70
50
30
65
39
130
20
SAR
30
190
100
80
50
50
50
50
30
50
10
20
59
46
190
10
NAV
70
70
100
130
110
130
50
20
30
60
70
30
73
36
130
20
ANC
40
60
60
50
110
80
80
40
100
100
10
150
73
36
150
10
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
GS
10
40
10
30
30
60
80
190
50
40
10
10
47
48
190
10
BRR
60
50
120
110
120
110
60
10
40
90
60
30
72
36
120
10
NC403
20
40
30
50
50
140
100
90
90
70
20
50
63
35
140
20
M61
70
80
110
100
110
110
60
20
40
80
70
40
74
29
110
20
PB
30
40
40
70
80
100
30
60
60
100
30
90
61
26
100
30
M54
90
240
120
170
120
110
50
20
50
70
60
40
95
60
240
20
LRC
30
50
30
40
80
70
50
50
80
70
40
370
80
89
370
30
M42
100
60
100
70
120
110
60
20
50
80
40
40
71
30
120
20
ROC
40
40
20
40
50
50
60
50
120
80
20
40
51
26
120
20
M35
90
40
30
30
120
50
70
10
60
60
20
40
52
30
120
10
BC117
50
1970
6510
160
140
210
150
110
60
80
60
30
794
1799
6510
30
M23
60
20
20
20
40
10
20
5
50
40
10
30
27
16
60
5
BCRR
40
50
10
50
80
360
30
50
50
40
40
20
68
90
360
10
M18
60
10
20
10
40
10
20
5
30
40
5
20
23
16
60
5
SPD
30
10
20
10
40
10
5
5
50
20
5
5
18
15
50
5
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
Table 2.11 Ammonium (µg/l) 2006 at the Lower Cape Fear River stations.
6RC
120
50
80
40
140
700
20
40
90
40
60
130
126
177
700
20
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
LCO
30
20
50
40
210
50
20
30
40
30
10
20
46
51
210
10
NC11
40
40
20
30
80
60
40
20
60
30
30
60
43
18
80
20
GCO
40
20
20
40
50
180
70
210
50
80
5
50
68
61
210
5
AC
90
30
60
50
110
260
90
30
100
50
50
60
82
59
260
30
SR
30
20
30
50
40
40
30
280
70
40
10
40
57
69
280
10
DP
80
30
50
110
100
180
70
40
100
80
70
70
82
38
180
30
BRN
40
20
40
30
30
50
40
60
130
40
30
140
54
38
140
20
IC
50
40
70
60
110
170
50
40
50
70
60
40
68
36
170
40
HAM
250
140
50
20
60
50
40
40
60
20
10
70
68
64
250
10
NCF6
30
60
60
40
40
20
40
30
30
40
60
30
40
13
60
20
71
33
129
17
68
17
57
70
48
45
107
99
129
BBT
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
NCF117
30
60
50
80
50
40
60
20
20
60
20
30
43
19
80
20
B210
10
40
40
50
40
60
30
10
20
30
10
10
29
17
60
10
COL
20
30
70
70
30
150
40
40
20
30
10
10
43
37
150
10
LVC2
70
260
660
240
180
280
120
30
90
140
170
60
192
161
660
30
32
HB
750
750
980
790
930
1,030
790
700
1,000
200
1,500
1,400
902
322
1,500
200
SAR
1,070
1,210
1,170
1,170
930
980
2,150
1,200
1,300
200
1,400
2,000
1,232
476
2,150
200
NAV
700
980
840
1,070
790
930
370
1,490
1,300
200
2,100
1,500
1,023
499
2,100
200
ANC
1,310
1,260
1,310
510
1,540
1,450
1,720
1,700
1,800
1,400
1,600
2,300
1,492
403
2,300
510
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
GS
750
560
700
980
840
1,400
190
1,300
1,800
200
1,800
1,700
1,018
554
1,800
190
BRR
750
790
890
700
930
750
700
750
900
200
900
1,700
830
320
1,700
200
NC403
610
420
700
790
890
1,170
1,490
1,600
1,000
200
2,200
1,600
1,056
553
2,200
200
M61
1,490
840
560
750
840
790
980
840
1,500
200
1,200
1,400
949
374
1,500
200
PB
650
1,120
1,030
1,260
560
930
1,030
1,300
1,300
1,200
900
1,300
1,048
241
1,300
560
M54
1,450
1,210
560
840
930
840
1,070
750
1,300
200
1,200
1,300
971
343
1,450
200
LRC
790
370
560
750
750
840
930
1,000
1,200
1,000
2,000
1,400
966
406
2,000
370
M42
980
930
930
930
980
890
840
840
1,100
200
200
1,900
893
413
1,900
200
ROC
930
750
980
930
890
1,120
1,210
1,300
1,400
1,000
2,000
1,200
1,143
315
2,000
750
M35
840
700
230
560
790
750
930
510
700
200
200
1,800
684
415
1,800
200
BC117
840
3,030
11,290
1,170
1,170
2,010
1,310
1,400
1,100
200
2,600
2,100
2,352
2,797
11,290
200
M23
750
650
190
1,070
650
280
890
230
800
200
1,000
2,200
743
534
2,200
190
BCRR
750
710
790
890
560
2,010
1,310
600
900
1,200
2,100
2,300
1,177
595
2,300
560
M18
1,630
560
190
330
610
190
610
280
800
200
200
200
483
401
1,630
190
SPD
700
420
280
5,270
700
190
650
230
1,000
200
200
200
837
1,361
5,270
190
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
6RC
930
750
930
1,070
330
930
700
1,100
1,700
200
1,700
1,800
1,012
491
1,800
200
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
LCO
890
980
610
1,170
1,590
1,030
1,260
900
1,400
200
1,100
1,300
1,036
354
1,590
200
NC11
840
610
650
700
700
750
1,050
280
900
200
1,200
2,100
832
468
2,100
200
GCO
890
790
890
9,430
1,030
1,170
750
1,600
1,000
200
1,200
200
1,596
2,392
9,430
200
AC
980
650
930
1,070
700
1,120
510
420
800
200
1,200
2,500
923
556
2,500
200
Table 2.12 Total Kjeldahl Nitrogen (µg/l) 2006 at the Lower Cape Fear River Program stations.
SR
650
700
560
1,260
1,030
930
1,170
1,900
1,500
200
2,000
1,800
1,142
548
2,000
200
DP
1,070
1,030
610
930
890
1,070
1,450
1,260
700
1,800
1,900
1,800
1,209
419
1,900
610
BRN
610
750
510
750
510
1,120
1,030
1,200
1,400
200
2,200
1,400
973
517
2,200
200
IC
1,070
790
610
930
930
980
1,120
980
1,000
200
1,800
2,000
1,034
456
2,000
200
HAM
930
750
650
610
1,070
700
980
700
1,300
200
1,200
1,900
916
411
1,900
200
NCF6
840
930
1,070
1,030
1,120
930
1,400
700
1,400
200
1,700
2,100
1,118
469
2,100
200
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
NCF117
980
1,030
610
1,030
1,120
650
1,490
750
1,200
200
200
1,100
863
376
1,490
200
B210
790
930
790
700
840
890
1,910
750
1,200
200
1,600
1,900
1,042
495
1,910
200
COL
1,350
890
1,260
1,120
980
1,310
1,590
840
1,200
200
2,200
2,100
1,253
520
2,200
200
LVC2
610
750
1,210
1,170
890
890
980
650
700
900
1,400
1,300
954
252
1,400
610
33
HB
80
70
80
230
150
60
70
110
80
120
70
90
101
46
230
60
SAR
80
70
90
140
140
150
180
220
180
110
90
90
128
46
220
70
NAV
90
100
100
140
170
90
50
190
80
150
80
90
111
40
190
50
ANC
130
70
100
170
240
220
280
240
270
150
360
110
195
83
360
70
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
GS
50
50
50
90
120
410
550
420
140
110
60
50
175
170
550
50
BRR
60
80
70
110
110
30
90
100
80
90
70
90
82
22
110
30
NC403
140
80
150
120
180
760
510
640
260
190
90
60
265
226
760
60
M61
60
80
70
80
70
40
110
90
90
100
70
100
80
19
110
40
PB
80
60
150
160
170
180
360
440
170
200
160
110
187
105
440
60
M54
60
100
60
140
80
30
100
100
120
70
40
150
88
36
150
30
LRC
30
40
20
60
70
30
40
100
120
80
80
50
60
29
120
20
M42
50
60
60
90
70
70
90
90
100
60
40
90
73
18
100
40
ROC
80
80
230
150
150
220
340
230
200
390
130
110
193
93
390
80
M35
60
50
50
60
60
40
60
100
60
50
30
90
59
18
100
30
BC117
290
590
840
560
710
390
1,920
690
210
2,810
150
290
788
757
2,810
150
M23
40
40
10
120
40
310
40
70
50
20
10
130
73
80
310
10
BCRR
120
30
40
100
80
310
160
110
120
40
90
20
102
75
310
20
M18
20
40
10
60
30
120
50
60
80
40
30
50
49
28
120
10
SPD
90
40
20
100
30
40
50
90
80
20
20
30
51
29
100
20
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
6RC
50
50
60
70
150
150
100
170
170
100
80
80
103
44
170
50
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
LCO
10
30
30
40
350
70
60
80
90
40
40
50
74
86
350
10
NC11
110
110
100
130
200
80
150
160
120
150
150
120
132
31
200
80
Table 2.13 Total Phosphorus (µg/l) 2006 at the Lower Cape Fear River Program stations.
GCO
140
190
310
240
260
780
660
350
340
160
80
80
299
209
780
80
AC
120
110
100
140
260
170
160
120
120
180
100
110
141
44
260
100
SR
30
40
60
70
70
80
10
230
140
100
40
60
78
56
230
10
DP
130
130
70
130
250
70
120
150
110
140
100
90
124
45
250
70
BRN
60
60
60
400
100
150
110
230
170
80
60
110
133
95
400
60
IC
80
80
80
460
170
100
110
130
120
120
120
60
136
102
460
60
HAM
80
60
70
130
130
150
110
220
160
120
110
110
121
42
220
60
NCF6
50
50
90
100
240
80
110
130
150
150
180
80
118
53
240
50
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
NCF117
40
40
40
70
100
60
150
160
170
140
80
80
94
47
170
40
B210
30
20
50
80
90
130
130
160
100
100
60
70
85
40
160
20
COL
50
10
30
70
30
60
50
110
40
50
30
40
48
24
110
10
LVC2
30
10
40
60
70
80
80
150
30
80
40
30
58
36
150
10
34
HB
50
40
40
50
70
60
70
40
40
60
50
30
50
12
70
30
SAR
10
20
40
40
40
40
70
40
90
50
40
30
43
20
90
10
NAV
40
40
50
60
60
60
50
60
10
60
50
20
47
16
60
10
ANC
70
50
60
100
110
100
180
150
270
130
270
100
133
71
270
50
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
GS
10
30
30
30
30
10
70
20
80
60
30
20
35
22
80
10
BRR
40
50
40
40
60
30
70
50
30
40
60
30
45
13
70
30
NC403
90
60
130
80
80
80
280
250
170
120
70
50
122
72
280
50
M61
30
30
30
30
50
40
80
60
40
30
50
30
42
15
80
30
PB
30
20
80
30
50
40
70
60
90
50
50
60
53
20
90
20
M54
40
80
20
30
40
40
60
40
40
30
40
30
41
15
80
20
LRC
10
10
10
10
10
10
40
20
40
20
10
20
18
11
40
10
M42
30
30
30
20
40
30
40
10
30
30
40
30
30
8
40
10
ROC
30
60
120
60
50
70
200
60
140
280
60
50
98
72
280
30
M35
30
20
20
20
40
30
50
40
30
30
30
30
31
9
50
20
BC117
200
430
550
560
110
300
1800
470
130
1860
100
300
568
586
1,860
100
M23
20
10
0
10
20
10
30
30
40
20
10
20
18
11
40
0
BCRR
30
10
10
20
10
100
40
30
60
10
30
0
29
27
100
0
M18
10
10
0
0
20
10
30
20
20
20
10
20
14
9
30
0
SPD
10
10
0
10
10
10
10
10
10
10
20
20
11
5
20
0
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
6RC
20
10
20
20
110
40
40
40
100
40
20
30
41
30
110
10
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
LCO
10
30
30
40
120
70
60
50
80
40
30
20
48
29
120
10
NC11
70
60
70
80
80
80
70
70
60
90
70
30
69
14
90
30
Table 2.14 Orthophosphate (µg/l) 2006 at the Lower Cape Fear River Program stations.
GCO
100
150
240
220
190
180
140
130
190
80
80
50
146
58
240
50
AC
70
50
70
90
120
120
70
60
50
130
80
30
78
30
130
30
SR
10
10
10
20
20
20
10
10
20
20
10
10
14
5
20
10
DP
70
40
40
70
100
70
60
70
50
70
50
30
60
18
100
30
BRN
20
20
20
20
30
20
40
60
80
10
20
40
32
20
80
10
IC
40
40
50
70
70
80
60
70
40
80
70
20
58
18
80
20
HAM
30
20
40
30
50
50
110
50
60
50
40
30
47
22
110
20
NCF6
20
20
30
30
40
40
80
30
90
80
40
30
44
24
90
20
24
27
17
31
17
28
27
8
41
55
212
8
BBT
21
39
212
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
B210
10
10
20
30
10
30
40
40
10
10
20
21
12
40
10
NCF117
20
20
20
30
40
40
60
110
70
10
40
42
28
110
10
40
10
20
10
10
20
13
50
10
COL
10
10
20
10
30
50
0
10
30
10
0
18
16
60
0
LVC2
10
10
20
30
20
60
35
M54
393
185
17
374
251
898
353
274
898
17
LRC
140
159
3
745
551
330
321
256
745
3
NAV
309
315
287
402
674
601
431
152
674
287
SAR
127
361
22
15
397
150
179
150
397
15
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
BC117
287
215
437
202
365
224
288
87
437
202
M35
176
267
38
464
216
611
295
190
611
38
6RC
276
148
119
3
286
374
201
124
374
3
M23
290
110
41
318
203
405
228
124
405
41
GCO
100
83
37
3
353
90
111
113
353
3
M18
392
161
3
367
162
251
223
133
392
3
NCF117
352
263
158
3
693
485
326
223
693
3
NC11
438
148
126
25
317
269
221
136
438
25
COL
643
799
69
538
1004
1025
680
325
1025
69
DP
390
201
412
58
431
601
349
174
601
58
Table 2.15 Aluminum (µg/l) 2006 at the Lower Cape Fear River
Program stations. There is no NC State standard.
LVC2
278
140
676
975
403
198
445
294
975
140
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
SAR
0
0
22
0
0
0
4
8
22
0
NAV
0
0
0
0
0
0
0
0
0
0
LRC
0
0
0
0
0
0
0
0
0
0
M54
0
0
0
0
0
0
0
0
0
0
BC117
0
0
0
0
0
0
0
0
0
0
M35
0
0
0
0
0
0
0
0
0
0
6RC
0
0
0
0
0
0
0
0
0
0
M23
0
0
0
0
0
0
0
0
0
0
GCO
0
0
0
0
0
0
0
0
0
0
M18
0
0
0
0
0
0
0
0
0
0
NCF 117
0
0
0
0
0
0
0
0
0
0
NC11
0
0
0
0
0
0
0
0
0
0
COL
0
0
0
0
0
0
0
0
0
0
DP
0
0
0
0
0
0
0
0
0
0
LVC2
0
0
0
0
0
0
0
0
0
0
Table 2.16 Arsenic (µg/l) 2006 at the Lower Cape Fear River
Program stations. The NC State standard is 10 mg/L for all stations.
36
M35
0
0
0
0
0
0
0
0
0
0
BC117
0
0
0
0
0
0
0
0
0
0
M54
0
0
0
0
0
0
0
0
0
0
LRC
0
0
0
0
0
0
0
0
0
0
NAV
0
0
0
0
0
0
0
0
0
0
SAR
0
0
0
0
0
0
0
0
0
0
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
6RC
0
0
0
0
0
0
0
0
0
0
M23
0
0
0
0
0
0
0
0
0
0
GCO
0
0
0
0
0
0
0
0
0
0
M18
0
0
0
0
0
0
0
0
0
0
NCF 117
0
0
0
0
0
0
0
0
0
0
NC11
0
0
0
0
0
0
0
0
0
0
COL
0
0
0
0
0
0
0
0
0
0
DP
0
0
0
0
0
0
0
0
0
0
LVC2
0
0
0
0
0
0
0
0
0
0
Table 2.17 Cadmium (µg/l) 2006 at the Lower Cape Fear River Program
stations. The NC State standard is 2.0 µg/L for freshwater and 5.0 µg/L for
saltwater.
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
SAR
0
0
0
0
0
0
0
0
0
0
NAV
0
0
0
0
0
0
0
0
0
0
LRC
0
0
0
0
0
0
0
0
0
0
M54
0
0
0
0
0
0
0
0
0
0
BC117
0
0
0
0
0
0
0
0
0
0
M35
0
0
0
0
0
0
0
0
0
0
6RC
0
0
0
0
0
0
0
0
0
0
M23
0
0
0
0
0
0
0
0
0
0
GCO
0
0
0
0
0
0
0
0
0
0
M18
0
0
0
0
0
0
0
0
0
0
NCF 117
0
0
0
0
0
0
0
0
0
0
NC11
0
0
0
0
0
0
0
0
0
0
COL
0
0
0
0
0
0
0
0
0
0
DP
0
0
0
0
0
0
0
0
0
0
LVC2
0
0
0
0
0
0
0
0
0
0
Table 2.18 Chromium (µg/l) 2006 at the Lower Cape Fear River Progr
stations. The NC State standard is 50 µg/L for freshwater and 20 µg/L
saltwater.
37
M54
0
0
0
0
0
0
0
0
0
0
LRC
0
0
0
0
0
0
0
0
0
0
NAV
0
0
0
0
0
0
0
0
0
0
SAR
0
0
0
0
0
0
0
0
0
0
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
BC117
0
0
0
0
0
0
0
0
0
0
M35
0
0
0
0
0
0
0
0
0
0
6RC
0
0
0
0
0
0
0
0
0
0
M23
0
0
0
0
0
0
0
0
0
0
GCO
0
0
0
0
0
0
0
0
0
0
M18
0
86
0
0
0
0
14
32
86
0
NCF 117
0
0
0
0
0
0
0
0
0
0
NC11
0
0
0
0
0
0
0
0
0
0
COL
0
0
0
0
0
0
0
0
0
0
DP
0
0
78
0
0
0
13
29
78
0
LVC2
0
0
0
0
0
0
0
0
0
0
Table 2.19 Copper (µg/l) 2006 at the Lower Cape Fear River Program
stations. The NC State standard is 7.0 µg/L for freshwater and 3.0 µg/L for
saltwater.
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
SAR
411
1320
1480
1240
1490
553
1082
435
1490
411
NAV
593
776
948
546
971
785
770
160
971
546
LRC
427
821
2200
1060
3160
1338
1501
920
3160
427
M54
671
343
174
497
529
1,080
549
284
1080
174
BC117
604
921
1890
730
1130
475
958
467
1890
475
M35
225
393
285
337
342
923
418
232
923
225
6RC
509
815
3480
1890
1324
681
1450
1017
3480
509
M23
412
245
294
263
262
573
342
117
573
245
GCO
243
527
2520
1590
997
248
1021
818
2520
243
M18
347
375
46
352
284
393
300
118
393
46
NCF117
456
579
756
525
927
673
653
156
927
456
NC11
757
428
852
533
764
676
668
145
852
428
COL
338
776
1185
954
1652
973
980
398
1652
338
DP
623
549
514
635
980
927
705
181
980
514
LVC2
655
1091
1163
188
986
565
775
341
1163
188
Table 2.20 Iron (µg/l) 2006 at the Lower Cape Fear River Program
stations. The NC State standard is 1,000 µg/L.
38
M54
0
0
0
0
0
0
0
0
0
0
LRC
0
0
0
0
0
0
0
0
0
0
NAV
0
0
0
0
0
0
0
0
0
0
SAR
0
0
0
0
0
0
0
0
0
0
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
BC117
0
0
0
0
0
0
0
0
0
0
M35
0
0
0
0
0
0
0
0
0
0
6RC
0
0
0
0
0
0
0
0
0
0
M23
0
0
0
0
0
0
0
0
0
0
GCO
0
0
0
0
0
0
0
0
0
0
M18
0
0
0
0
0
0
0
0
0
0
NCF 117
0
0
0
0
0
0
0
0
0
0
NC11
0
0
0
0
0
0
0
0
0
0
COL
0
0
0
0
0
0
0
0
0
0
DP
0
0
13
0
0
0
2
5
13
0
LVC2
0
0
0
0
0
0
0
0
0
0
Table 2.21 Lead (µg/l) 2006 at the Lower Cape Fear River Program
stations. The NC State standard is 25 µg/L.
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
SAR
0
0
0
0
0
0
0
0
0
0
NAV
0
0
0
0
0
0
0
0
0
0
LRC
0
0
0
0
0
0
0
0
0
0
M54
0
0
0
0
0
0
0
0
0
0
BC117
0
0
0
0
0
0
0
0
0
0
M35
0
0
0
0
0
0
0
0
0
0
6RC
0
0
0
0
0
0
0
0
0
0
M23
0
0
0
0
0
0
0
0
0
0
GCO
0
0
0
0
0
0
0
0
0
0
M18
0
0
0
0
0
0
0
0
0
0
NCF 117
0
0
0
0
0
0
0
0
0
0
NC11
0
0
0
0
0
0
0
0
0
0
COL
0
0
0
0
0
0
0
0
0
0
DP
0
0
0
0
0
0
0
0
0
0
LVC2
0
0
0
0
0
0
0
0
0
0
Table 2.22 Mercury (µg/l) 2006 at the Lower Cape Fear River Program
stations. The NC State standard is 0.012 µg/L for freshwater and 0.025
for saltwater.
39
M35
0
0
0
0
0
0
0
0
0
0
BC117
0
0
0
0
0
0
0
0
0
0
M54
0
0
0
0
0
0
0
0
0
0
LRC
0
0
0
0
0
0
0
0
0
0
NAV
0
0
0
0
0
0
0
0
0
0
SAR
0
0
0
0
0
0
0
0
0
0
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
6RC
0
0
0
0
0
0
0
0
0
0
M23
0
0
0
0
0
0
0
0
0
0
GCO
0
0
6
0
0
0
1
2
6
0
M18
0
16
0
0
0
0
3
6
16
0
NCF 117
0
0
0
0
0
0
0
0
0
0
NC11
0
0
0
0
0
0
0
0
0
0
COL
0
0
0
0
10
0
2
4
10
0
DP
0
0
0
0
0
0
0
0
0
0
LVC2
0
0
0
0
0
0
0
0
0
0
Table 2.23 Nickel (µg/l) 2006 at the Lower Cape Fear River Program
stations. The NC State standard is 88 µg/L for freshwater and 8.3 µg/L
for saltwater.
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
FEB
APR
JUN
AUG
OCT
DEC
mean
std dev
max
min
SAR
0
13
0
0
0
0
2
5
13
0
NAV
0
22
0
0
0
0
4
8
22
0
LRC
0
14
0
0
0
0
2
5
14
0
M54
0
0
0
0
0
0
0
0
0
0
BC117
12
31
0
0
0
0
7
12
31
0
M35
15
0
0
0
0
0
3
6
15
0
6RC
0
0
0
14
0
0
2
5
14
0
M23
0
14
0
0
0
0
2
5
14
0
GCO
0
0
0
0
0
0
0
0
0
0
M18
0
133
0
0
0
0
22
50
133
0
NCF 117
0
18
0
0
0
0
3
7
18
0
NC11
0
15
0
0
0
0
3
6
15
0
COL
0
14
0
0
0
0
2
5
14
0
DP
0
13
135
0
0
0
25
50
135
0
LVC2
0
17
0
0
0
0
3
6
17
0
Table 2.24 Zinc (µg/l) 2006 at the Lower Cape Fear River Program
stations. The NC State standard is 50 µg/L for freshwater and 86 µg/L
for saltwater.
40
HB
1.0
5.2
2.2
2.5
1.5
6.1
0.5
5.1
1.0
1.3
2.2
1.8
2.5
1.8
6.1
0.5
SAR
5.1
0.7
0.6
1.5
1.1
1.4
1.3
4.4
0.6
0.4
1.2
0.6
1.6
1.5
5.1
0.4
NAV
1.4
4.7
3.6
2.3
1.7
3.2
0.3
5.4
1.0
1.5
1.2
1.7
2.3
1.5
5.4
0.3
ANC
1.4
2.1
2.8
2.6
3.9
1.9
4.3
4.5
0.3
0.7
0.8
0.7
2.2
1.4
4.5
0.3
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
GS
6.4
1.4
0.9
1.5
1.3
7.5
30.4
17.1
1.4
1.4
0.8
0.7
5.9
8.7
30.4
0.7
BRR
1.5
5.9
2.8
6.3
1.2
4.6
1.3
9.6
1.5
3.7
1.2
1.8
3.5
2.6
9.6
1.2
NC403
3.5
2.0
1.1
0.9
2.3
5.1
8.7
13.0
1.6
2.4
1.5
3.7
3.8
3.5
13.0
0.9
0.2
11.7
1.6
1.7
1.4
2.0
3.2
3.0
11.7
0.2
M61
1.6
4.4
3.2
5.3
1.6
PB
2.3
8.0
11.4
6.1
4.9
3.8
36.5
14.4
1.0
4.8
2.0
2.1
8.1
9.4
36.5
1.0
M54
1.7
5.3
3.2
3.2
2.6
8.0
1.5
5.6
2.7
2.1
2.7
0.9
3.3
1.9
8.0
0.9
LRC
1.6
1.4
1.2
0.3
0.7
0.4
19.7
3.8
1.7
1.3
7.3
1.8
3.4
5.2
19.7
0.3
M42
1.7
4.9
1.9
4.7
3.6
11.4
1.4
13.6
2.3
2.9
2.5
1.2
4.3
3.8
13.6
1.2
ROC
2.9
0.7
0.5
1.1
0.9
0.8
0.6
2.3
0.8
0.3
1.0
0.5
1.0
0.7
2.9
0.3
M35
1.5
6.6
2.4
4.9
3.4
12.4
1.6
9.5
2.5
3.0
2.3
0.9
4.3
3.4
12.4
0.9
BC117
1.2
2.6
2.6
3.1
0.9
7.0
3.0
1.3
0.6
1.1
0.7
0.5
2.1
1.8
7.0
0.5
M23
3.6
5.6
3.4
4.0
4.5
12.7
1.3
10.0
3.1
3.6
3.3
0.8
4.7
3.3
12.7
0.8
BCRR
3.5
1.5
2.0
2.2
0.6
6.0
29.8
4.1
0.4
7.7
0.5
0.2
4.9
7.8
29.8
0.2
0.9
8.5
2.3
3.0
6.2
1.7
4.4
2.8
9.5
0.9
M18
1.9
7.5
9.5
3.5
3.6
SPD
2.2
5.7
4.8
4.7
4.1
9.8
0.6
17.2
10.2
5.5
3.3
2.0
5.8
4.4
17.2
0.6
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
6RC
1.2
0.9
0.5
0.5
2.5
0.5
0.2
1.4
0.8
0.4
0.3
0.9
0.8
0.6
2.5
0.2
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
LCO
1.4
0.8
0.6
0.5
2.2
0.5
0.5
0.4
0.3
1.1
0.6
0.7
0.8
0.5
2.2
0.3
NC11
1.6
4.0
6.2
15.2
2.4
7.4
1.2
9.7
1.2
8.4
0.7
1.8
5.0
4.3
15.2
0.7
GCO
1.7
0.5
0.8
1.1
2.1
1.1
2.0
1.0
0.9
1.5
0.7
0.9
1.2
0.5
2.1
0.5
AC
1.2
4.1
5.1
11.9
2.0
9.5
1.0
9.1
0.7
3.1
0.7
2.1
4.2
3.7
11.9
0.7
SR
3.6
0.8
1.0
2.9
2.5
2.6
1.1
7.3
2.1
3.9
0.8
1.4
2.5
1.8
7.3
0.8
DP
1.4
4.5
3.6
11.0
2.1
4.4
1.1
7.0
1.0
1.5
0.5
2.5
3.4
2.9
11.0
0.5
BRN
1.0
1.1
1.1
3.7
1.2
0.9
0.4
1.3
1.7
0.7
0.4
0.8
1.2
0.8
3.7
0.4
BBT
0.8
2.2
2.9
5.2
0.9
1.1
0.4
4.3
0.3
0.9
0.4
0.6
1.7
1.6
5.2
0.3
HAM
3.0
1.1
1.1
1.0
2.0
0.9
0.8
0.6
1.3
2.5
0.2
0.6
1.3
0.8
3.0
0.2
IC
1.0
6.0
3.6
5.2
1.5
2.1
0.7
4.7
0.5
1.1
0.5
1.4
2.4
1.9
6.0
0.5
NCF6
1.9
0.7
1.6
4.0
6.7
10.6
0.2
8.3
0.5
1.4
1.6
0.6
3.2
3.3
10.6
0.2
Table 2.25 Chlorophyll a (µg/l) 2006 at the Lower Cape Fear River Program stations. The NC State standard is 40 µg/L.
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
B210
0.9
0.6
0.4
0.4
0.4
1.0
1.9
1.1
0.3
0.2
0.4
0.7
0.5
1.9
0.2
NCF117
1.6
0.3
1.5
0.3
0.4
1.4
1.2
0.6
0.2
0.1
0.4
0.7
0.5
1.6
0.1
0.9
0.4
0.2
0.3
0.3
1.0
0.7
2.5
0.2
COL
0.3
1.1
2.1
1.4
1.1
2.5
7.8
0.8
1.4
0.6
1.0
1.8
2.0
7.8
0.6
LVC2
1.1
1.1
1.2
1.1
0.8
2.8
41
NC11
0.7
1.0
1.1
1.6
1.3
1.7
1.3
1.2
1.5
1.7
2.0
1.3
1.3
1.4
2.0
0.7
0.4
AC
1.1
1.0
1.2
1.9
1.3
2.4
2.2
1.7
2.1
1.7
1.1
1.4
1.6
1.6
2.4
1.0
0.5
SAR
1.1
1.3
1.5
1.7
1.4
1.5
1.4
0.8
1.3
0.7
1.4
1.3
1.7
0.7
0.3
ANC
1.4
1.3
2.9
2.1
2.3
2.2
1.6
2.2
0.9
1.9
0.9
1.9
1.8
2.9
0.9
0.6
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
median
mean
max
min
stdev
AC
3.2
2.9
3.5
4.8
3.5
6.4
5.0
4.0
5.1
3.8
3.6
3.8
4.2
6.4
2.9
1.0
NC11
2.3
2.8
2.7
4.1
3.3
4.3
3.0
3.1
3.8
3.6
4.6
3.3
3.4
4.6
2.3
0.7
3.9
3.9
4.6
2.9
0.6
2.9
4.3
6.1
4.7
5.8
5.5
5.3
6.4
3.7
1.0
SAR
3.2
4.6
4.1
4.6
3.4
3.9
3.7
ANC
3.8
3.7
6.4
5.6
5.2
6.2
5.4
20-Day Biochemical Oxygen Demand
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
median
mean
max
min
stdev
5-Day Biochemical Oxygen Demand
4.1
4.4
8.5
2.6
1.9
4.7
4.8
2.6
GS
3.1
5.3
3.4
3.0
2.7
8.5
6.1
1.9
2.0
0.9
0.8
1.4
1.7
3.4
0.8
0.8
GS
1.2
2.0
0.9
1.2
1.4
3.4
2.6
4.7
5.0
8.6
2.3
2.1
N403
2.3
4.4
2.8
3.5
3.1
8.2
6.0
6.5
4.7
5.4
8.6
N403
1.1
1.6
1.1
1.3
1.5
2.8
2.3
2.5
1.9
2.3
4.7
0.9
1.8
2.0
4.7
0.9
1.0
4.2
4.3
6.0
3.1
1.0
ROC
4.5
3.1
3.1
5.0
3.8
3.7
3.4
6.0
5.9
4.9
4.2
ROC
1.9
1.2
1.1
2.0
1.8
1.4
1.2
2.1
2.3
1.9
1.9
1.1
1.9
1.7
2.3
1.1
0.4
5.3
7.0
23.8
3.2
5.9
3.5
3.5
5.0
2.6
0.8
3.6
3.7
6.8
2.1
1.4
BC117 NCF117 B210
4.7
2.7
2.1
8.4
4.4
4.3
23.8
2.6
2.5
6.6
2.4
4.0
3.8
3.5
8.7
2.6
3.9
5.3
5.3
3.5
6.8
4.1
5.0
4.6
3.2
3.7
2.9
3.3
3.5
3.6
BC117 NCF117 B210
1.9
0.9
1.2
2.4
1.5
1.4
8.8
0.6
0.8
1.4
0.9
1.7
1.4
1.2
4.1
0.9
1.6
1.5
1.7
1.4
3.6
1.5
2.1
1.8
1.0
1.2
1.1
1.3
1.2
1.5
0.9
0.8
0.8
1.6
1.2
1.2
2.4
1.2
1.4
8.8
2.1
3.6
0.9
0.6
0.8
2.2
0.4
0.8
4.7
5.0
8.2
3.0
1.6
8.2
4.1
3.1
6.1
LVC2
3.0
5.9
5.9
4.8
3.8
4.6
3.5
2.1
1.0
2.3
0.9
1.7
1.7
3.5
0.9
0.7
LVC2
1.1
1.7
1.7
1.7
1.5
1.7
3.4
3.9
6.9
2.0
1.4
BBT
2.0
3.2
3.2
6.9
3.3
4.4
3.5
3.4
4.4
3.4
5.7
BBT
0.7
1.3
1.1
1.5
1.1
1.6
1.2
1.4
1.7
1.3
2.3
0.9
1.3
1.3
2.3
0.7
0.4
Table 2.26 Biochemical Oxygen Demand (mg/l) 2006 at the Lower Cape Fear River Program stations.
42
HB
25
11
20
42
62
40
17
58
320
40
78
88
67
80
320
11
44
SAR
240
44
67
96
237
220
300
900
800
200
360
400
322
259
900
44
230
NAV
25
18
11
13
66
50
33
40
480
22
84
37
73
124
480
11
38
ANC
180
52
44
78
84
220
52
700
145
73
560
80
189
206
700
44
121
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
Geomean
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
Geomean
GS
62
27
29
146
62
200
340
3000
100
280
84
108
370
799
3000
27
130
BRR
20
13
9
22
27
84
20
120
120
40
92
40
51
40
120
9
36
NC403
140
35
164
52
84
180
92
800
650
173
440
80
241
241
800
35
154
M61
52
9
11
11
40
19
71
20
140
26
94
84
48
40
140
9
33
PB
124
60
160
750
124
1,300
600
3,000
1000
6000
112
96
1111
1681
6000
60
400
M54
36
7
14
15
56
30
400
74
480
39
52
31
103
153
480
7
46
LRC
108
180
59
41
86
250
128
750
2250
46
880
120
408
616
2250
41
179
M42
44
5
24
2
25
48
1100
19
220
8
40
40
131
297
1100
2
31
ROC
116
90
52
80
149
260
156
3000
900
73
400
80
446
803
3000
52
185
M35
25
1
4
1
33
17
750
6
180
1
6
33
88
205
750
1
12
BC117
650
63
400
41
800
4200
64
1600
2700
430
620
164
978
1220
4200
41
417
M23
7
1
2
4
5
2
41
1
120
1
2
44
19
34
120
1
5
BCRR
540
350
314
308
271
3800
144
1800
2150
46
360
13
841
1105
3800
13
338
M18
9
5
7
10
13
1
28
4
80
6
1
13
15
21
80
1
7
SPD
9
1
13
6
8
10
22
2
56
10
6
60
17
19
60
1
9
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
Geomean
6RC
80
47
86
19
1200
1
55
144
170
55
62
255
181
315
1200
1
67
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
Geomean
LCO
108
46
29
15
1800
31
164
56
73
45
70
200
220
479
1800
15
78
NC11
22
5
11
1
54
2
11
180
148
11
68
48
47
57
180
1
18
GCO
120
25
20
12
560
10
38
26
100
45
17
91
89
147
560
10
42
AC
18
5
14
6
72
20
17
1200
212
6
46
60
140
324
1200
5
31
SR
76
30
46
33
1200
92
91
3000
160
91
18
91
411
841
3000
18
108
DP
9
18
27
8
66
24
19
35
289
17
160
76
62
80
289
8
34
BRN
160
58
73
49
150
22
800
200
1250
185
84
6000
753
1621
6000
22
189
IC
24
18
46
8
64
11
26
30
120
37
112
54
46
35
120
8
34
HAM
880
110
140
120
1200
128
146
232
700
250
98
700
392
361
1200
98
261
NCF6
44
25
60
46
64
58
20
160
228
60
104
40
76
58
228
20
60
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
mean
std dev
max
min
Geomean
NCF117
50
18
52
35
35
33
42
500
1200
46
76
42
177
333
1200
18
66
B210
53
48
36
19
40
40
42
137
400
54
260
64
99
110
400
19
65
COL
20
29
27
35
38
42
22
160
220
46
140
35
68
64
220
20
48
Table 2.27 Fecal Coliform (cfu/100 ml) 2006 at the Lower Cape Fear River Program stations. The NC State standard is 200 cfu/100 mL for all stations
except SPD and M23 due to their status as shellfishing waters (14 cfu/100 mL).
LVC2
29
24
25
66
80
68
88
1200
1200
42
1560
70
371
555
1560
24
111
90
74
180
42
88
72
700
560
116
380
35
212
219
700
35
131
SC-CH
43
Salinity (psu)
0
5
10
15
20
25
30
NAV
HB
BRR
M61
M54
M42
M35
M23
M18
SPD
NCF6
Figure 2.1 Salinity at the Lower Cape Fear River Program estuarine stations, 1995‐2005 versus 2006.
2006
1995‐2005
44
Dissolved Oxygen (mg/L)
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
NC11
AC
DP
IC
NAV
HB
BRR
M61
M54
M42
M35
M23
M18
B210
2006
1995‐2005
NCF117 NCF6
Figure 2.2 Dissolved Oxygen at the Lower Cape Fear River Program mainstem stations, 1995‐2005 versus 2006.
BBT
45
Field Turbidity (NTU)
0
5
10
15
20
25
30
NC11
AC
DP
IC
NAV
HB
BRR
M61
M54
M42
M35
M23
M18
NCF117 NCF6
2006
B210
1995‐2005
Figure 2.3 Field Turbidity at the Lower Cape Fear River Program mainstem stations, 1995‐2005 versus 2006.
BBT
46
Total Nitrogen (µg/L)
0
200
400
600
800
1000
1200
1400
1600
1800
NC11
AC
DP
IC
NAV
HB
BRR
M61
M54
M42
M35
M23
M18
NCF117 NCF6
2006
1995‐2005
Figure 2.4 Total Nitrogen at the Lower Cape Fear River Program mainstem stations, 1996‐2005 versus 2006.
B210
47
Total Phosphorus (µg/L)
0
20
40
60
80
100
120
140
160
180
200
NC11
AC
DP
IC
NAV
HB
BRR
M61
M54
M42
M35
M23
M18
NCF117
Figure 2.5 Total Phosphorus at the Lower Cape Fear River Program mainstem stations, 1995‐2005 versus 2006.
NCF6
2006
B210
1995‐2005
48
Fecal Coliform Bacteria (cfu/100 mL)
0
20
40
60
80
100
120
140
160
180
200
NC11
AC
DP
IC
NAV
HB
BRR
M61
M54
M42
M35
M23
M18
NCF117
2006
B210
1996‐2005
NCF6
Figure 2.6 Fecal Coliform Bacteria at the Lower Cape Fear River Program mainstem stations, 1996‐2005 versus 2006.
3.0 Water Quality Evaluation by Subbasin in the Lower Cape Fear River System
Matthew R. McIver, Michael A. Malin and James F. Merritt
Aquatic Ecology Laboratory
Center for Marine Science
University of North Carolina Wilmington
This section details an evaluation of water quality within each subbasin for dissolved
oxygen, turbidity, chlorophyll a, fecal coliform bacteria and some nutrient species at the
LCFRP sampling sites. Monthly data from January to December 2006 are used in the
comparisons.
3.1 Introduction
The NC Division of Water Quality prepares a basinwide water quality plan for each of
the seventeen major river basins in the state every five years (NCDENR, DWQ Cape
Fear River Basinwide Water Quality Plan, October 2005). The basinwide approach is a
nonregulatory watershed-based approach to restoring and protecting the quality of
North Carolina’s surface waters. The first basinwide plan for the Cape Fear River was
completed in 1996 and five-year interval updates have been completed in 2000 and
2005.
The goals of the basinwide program are to:
- Identify water quality problems and restore full use to Impaired waters.
- Identify and protect high value resource waters.
- Protect unimpaired waters while allowing for reasonable economic growth.
DWQ accomplishes these goals through the following objectives:
- Collaborate with other agencies to develop appropriate management strategies.
- Assure equitable distribution of waste assimilative capacity.
- Better evaluate cumulative effects of pollution.
- Improve public awareness and involvement.
The US Geological Survey (USGS) identifies 6 major hydrological areas in the Cape
Fear River Basin. Each of these hydrologic areas is further divided into subbasins by
DWQ. There are 24 subbasins within the Cape Fear River basin, each denoted by 6digit numbers, 03-06-01 to 03-06-24 (NCDENR-DWQ, October 2005).
All surface waters in the state are assigned a primary classification that is appropriate to
the best uses of that water. North Carolina’s Water Quality Standards Program adopted
classifications and water quality standards for all the state’s river basins by 1963. The
program remains consistent with the Federal Clean Water Act and its amendments.
DWQ assesses ecosystem health and human health risk through the use of five use
support categories: aquatic life, recreation, fish consumption, water supply and shellfish
49
harvesting. [Note: All waters east of Interstate 95 are considered impaired for fish
consumption due to mercury levels in fish tissue.] These categories are tied to the uses
associated with the primary classifications applied to NC rivers and streams. Waters
are supporting if data and information used to assign a use support rating meet the
criteria for that use category. If these criteria are not met then the waters are Impaired.
Waters with inconclusive data and information are Not Rated. Waters where insufficient
data or information are available to make an assessment are rated No Data.
For ambient water quality monitoring criteria, DWQ uses water quality data collected by
both their own monitoring system as well as several NPDES discharger coalitions
including the Lower Cape Fear River Program. The parameters used to assess water
quality in the aquatic life category include dissolved oxygen (DO), pH, chlorophyll a and
turbidity as well as benthos and fish data. DWQ rates use support based on whether
the NC State Water Quality Standard is exceeded as listed below:
Standard exceeded in < 10% of samples
Standard exceeded in > 10% of samples
Less than 10 samples collected
DO and pH standard exceeded in swamps
=
=
=
=
Supporting
Impaired
Not Rated
Not Rated
*Some standards are written with more specific criteria and the reader should refer to
the Basinwide Water Quality plan for complete details about the DWQ rating system
(refer).
3.2 Methods
The UNCW Aquatic Ecology Laboratory (AEL) has developed an evaluation system that
incorporates some of the guidelines used by DWQ and utilizes data collected by the
Lower Cape Fear River Program. This approach determines a water quality “rating” for
the parameters dissolved oxygen, chlorophyll a, fecal coliform bacteria, field turbidity
and the nutrient species nitrate-nitrite (referred to as nitrate) and total phosphorus. For
dissolved oxygen, chlorophyll a, and fecal coliform bacteria we compare LCFRP data to
the N.C. State Water Quality Standards (http://h2o.enr.state.nc.us/csu/index.htm).
Fecal coliform bacteria data is analyzed considering human contact standards, not
shellfishing standards.
The NC DWQ does not have surface water quality standards for nitrate and total
phosphorus. The AEL water quality status is based on levels noted to be problematic in
the scientific literature and our own published research. Based on data from four years
of nutrient addition bioassay experiments using water from the Black and Northeast
Cape Fear Rivers, Colly Creek and Great Coharie Creek: the UNCW-AEL considers
total phophorus levels of 500 µg/L potentially harmful to water quality in all the waters of
the Cape Fear River watershed. Nitrate levels of 200 µg/L, 500 µg/L and 1,000 µg/L in
small streams, mainstem blackwater stations (NCF117, NCF6, B210) and mainstem
Cape Fear River stations, respectively, are considered harmful to water quality. These
nutrient levels may lead to algal blooms, high bacteria levels and high biochemical
50
oxygen demand (BOD) in blackwater streams (Mallin et al., 2001; 2002; 2004). Water
quality status for nutrient species at the mainstem Cape Fear River stations was
evaluated with a higher standard for nutrients because its waters are quite different than
the blackwater areas and are able to better assimilate higher nutrient levels.
Our system lists a sampling location as having good quality (G) if the standard is
exceeded in none or 1 sample out of 12 measurements (<10%), fair quality (F) if
standard is exceeded in 2 or 3 or 12 of measurements (11-25%), or poor quality (P) if
standard is exceeded in 4-12 out of 12 measurements (>25%).
The 36 stations monitored by the LCFRP by subbasin:
Subbasin #
03-06-16
LCFRP Stations
BRN, HAM, NC11
03-06-17
LVC2, AC, DP, IC, NAV, HB, BRR,
M61, M54, M42, M35, M23, M18, SPD
03-06-18
SR
03-06-19
6RC, LCO, GCO
03-06-20
COL, B210, BBT
03-06-21
N403
03-06-22
SAR, GS, PB, LRC, ROC
03-06-23
ANC, BC117, BCRR, NCF6, NCF117,
SC-CH
Each subbasin is addressed separately with a description and map showing the LCFRP
stations. This will be followed by a summary of the information published in the October
2005 Cape Fear River Basinwide Water Quality Plan and water quality status
discussion using the UNCW-AEL approach for the 2006 LCFRP data.
51
3.3 Cape Fear River Subbasin 03-06-16
Location:
Cape Fear River upstream and downstream of Elizabethtown
Counties:
Bladen, Columbus, Cumberland, Pender
Water bodies:
Cape Fear River
Municipalities:
Elizabethtown, Dublin, White Lake, East Arcadia, Tar Heel
NPDES Dischargers: 7 @ 13.7 million gallons per day
Concentrated Swine Operations: 50
LCFRP monitoring stations (DWQ #):
BRN (B8340050), HAM (B8340200), NC11 (B8360000)
NC DWQ monitoring stations (DWQ #):
Six ambient monitoring stations
BRN
HAM
NC1
52
Subbasin 03-06-16 includes the Cape Fear River and many streams that drain coastal plain
wetlands and bay lakes. Most of the watershed is forested with some agriculture present.
The CFR Basinwide Water Quality Plan lists the following ratings for this subbasin:
Aquatic Life
Supporting
Not Rated
Not Rated
No Data
No Data
101.5 freshwater miles
40.1 freshwater miles
1,593.2 freshwater acres
131.4 freshwater miles
917.6 freshwater acres
Recreation
Supporting
Not Rated
No Data
No Data
115.1 freshwater miles
4.8 freshwater miles
153.1 freshwater miles
2,510.8 freshwater acres
*Brown’s Creek, rated as impaired in the 2000 CFRBWQP, was upgraded in the 2005 plan
(NCDENR DWQ CFRWQBP, July 2000 and NCDENR DWQ CFRWQBP, October 2005).
Lower Cape Fear River Program Evaluation
Data collection: NC11 since June 1995, BRN & HAM since February 1996
Sampling relevance: Represents water entering the Lower Cape Fear River watershed from
the middle basin (NC11). There are also concentrated animal operations within the area (BRN
and HAM).
BRN - representative of small tributaries
of the Cape Fear River
NC11 - main stem of Cape Fear River,
deep channel, freshwater
with slight tidal influence
53
All three sites in this subbasin had a good rating for dissolved oxygen, meeting the North
Carolina State standard in all sampled months (Table 3.3.1).
All sites within this subbasin had a good rating for chlorophyll a concentrations (Table 3.3.1).
The North Carolina State standard for chlorophyll a of 40 µg/L was not exceeded at any station
during 2006.
Fecal coliform bacteria concentrations were low at NC11 which had a good rating with no
sample over the NC State Standard for human contact waters of 200 CFU/100mL in 2006
(Table 3.3.1). BRN and HAM received a poor rating for fecal coliform bacteria concentrations
exceeding the standard 33% of the time (Figure 3.3.1).
All sites within this subbasin were found to have a good rating for field turbidity concentrations
(Table 3.3.1). The North Carolina State Standard for turbidity of 50 NTU was not exceeded at
any station during 2006.
For nitrate, BRN rated as poor (42% above standard) and HAM rated as fair (25% above
standard). A good rating was found at NC11 for both nutrient species and for total phosphorus
at BRN and HAM.
Table 3.3.1 UNCW AEL 2006 evaluation for subbasin 03-06-16
Station
Dissolved Oxygen
Chlorophyll a
Fecal Coliform
Field Turbidity
Nitrate
Total
Phosphorus
BRN
G
G
P
G
P
G
HAM
G
G
P
G
F
G
NC11
G
G
G
G
G
G
54
Aquatic Ecology Laboratory, UNC Wilmington
55
Aquatic Ecology Laboratory, UNC Wilmington
56
3.4 Cape Fear River Subbasin 03-06-17
Location:
Cape Fear River near Riegelwood, downstream to estuarine area
near Southport
Counties:
Columbus, Pender, Brunswick, New Hanover
Waterbodies:
Cape Fear River and Estuary
Municipalities:
Wilmington, Southport
NPDES Dischargers: 41 @ 99.9 million gallons per day
Concentrated Swine Operations: 7
LCFRP monitoring stations (DWQ #):
LVC2 (B8445000), AC (B8450000), DP (B8460000), IC (B9030000),
NAV (B9050000), HB (B9050100), BRR (B9790000), M61 (B9750000),
M54 (B9795000), M42 (B9845100), M35 (B9850100), M23 (B9910000),
M18 (B9921000), SPD (B9980000)
DWQ monitoring stations:
NAV (B9050000), M61 (B9750000), M54(B9795000)
LV
DP
A
IC
NAV
HB
BRR
M61
M54
M42
M35
M23
M18
SPD
57
Subbason 03-06-17 includes the mainstem of the Cape Fear River, the Cape Fear River
Estuary and many streams that drain the areas west of the River. Most of the watershed is
forested with some urban areas including Wilmington and Southport.
CFR Basinwide Water Quality Plan lists the following ratings for this subbasin:
Aquatic Life
Supporting
Not Rated
Impaired
Supporting
Not Rated
Not Rated
No Data
No Data
No Data
No Data
14,125.4 saltwater acres
2.0 saltwater acres
6,457.0 saltwater acres
75.4 freshwater miles
22.3 freshwater miles
406.9 freshwater acres
2,859.2 saltwater acres
215.4 freshwater miles
844.5 freshwater acres
22.8 coast miles
Recreation
Supporting
Impaired
Supporting
Not Rated
Impaired
No Data
No Data
No Data
No Data
21,092.3 saltwater acres
96.6 saltwater acres
44.1 freshwater miles
5.6 coast miles
4.7 coast miles
2,254.6 saltwater acres
269.1 freshwater miles
1,251.5 freshwater acres
12.5 coast miles
Lower Cape Fear River Program Assessment
Data collection: Most stations since 1995, all sampled since 1998
Sampling relevance: Highly important estuary for fisheries productivity. Also receives point
source discharge and non-point source pollution.
AC - representative of riverine system
channel
HB - riverine station, upstream of
HB – upper estuary, upstream of
Wilmington
58
M35 – represents wide estuary
Sites given a good rating for dissolved oxygen include LVC2, AC, DP, IC, M35, M23 and M18
(Table 3.4.1). Sites having a fair rating for dissolved oxygen, with the percentage of samples
not meeting the standard shown in parentheses, are BRR (25%), M42 (17%) and SPD (17%).
Sites having poor rating for dissolved oxygen, with the percentage of samples not meeting the
standard shown in parentheses, are NAV (33%), HB (42%), M61 (33%) and M54 (33%).
All sites within this subbasin had a good rating in terms of chlorophyll a concentrations (Table
3.4.1). None of the sampled locations exceeded the 40 µg/L North Carolina State standard on
any sample occasion during 2006.
Sites within this subbassin rated as good quality for fecal coliform bacteria concentrations
include DP, IC, NAV, HB, BRR, M61, M35, M23, M18, SPD (Table 3.4.1). Sites having a fair
rating for Fecal coliform bacteria, with the percentage of samples not meeting the standard
shown in parentheses, are LVC2 (25%), AC (17%), M54 (17%) and M42 (17%). No sites had
a poor rating during 2006.
All the LCFRP sites in this subbasin had a good rating for field turbidity except M54 (rated fair
with 17% of samples above the standard) in the middle estuary (Table 3.4.1). The station NAV
and those upstream were evaluated using the NC State Standard for freshwater of 50 NTU
while all stations downstream of NAV were evaluated with the NC State Standard for brackish
waters of 25 NTU.
All the LCFRP sites in this subbasin had a good rating for nitrate and total phosphorus except
LVC2 (Table 3.4.1). LVC2 exceeded the standard for nitrate 17% of the time for a fair quality
status.
59
Table 3.4.1 UNCW AEL 2006 evaluation for subbasin 03-06-17
Station
Dissolved Oxygen
Chlorophyll a
Fecal Coliform
Field Turbidity
Nitrate
Total
Phosphorus
LVC2
G
G
F
G
F
G
AC
G
G
F
G
G
G
DP
G
G
G
G
G
G
IC
G
G
G
G
G
G
NAV
P
G
G
G
G
G
HB
P
G
G
G
G
G
BRR
F
G
G
G
G
G
M61
P
G
G
G
G
G
M54
P
G
F
F
G
G
M42
F
G
F
G
G
G
M35
G
G
G
G
G
G
M23
G
G
G
G
G
G
M18
G
G
G
G
G
G
SPD
F
G
G
G
G
G
60
Figure 3.4.1 Dissolved oxygen concentrations (mg/L) at NAV, HB and M61 for 2005. The
dashed line shows the NC State Standard of 5.0 mg/L.
12
Dissolved Oxygen (mg/L)
10
8
6
4
NAV
HB
2
M61
0
JAN
FEB MAR APR MAY JUN
JUL
61
AUG SEP OCT NOV DEC
3.5 Cape Fear River Subbasin 03-06-18
Location:
South River headwaters above Dunn down to Black River
Counties:
Bladen, Cumberland, Harnett, Johnston, Sampson
Waterbodies:
South River, Mingo Swamp
Municipalities:
Dunn, Roseboro
NPDES Dischargers: 2 @ 0.08 million gallons per day
Concentrated Swine Operations: 105
LCFRP monitoring stations (DWQ #): SR (B8470000)
DWQ monitoring stations:
none
SR
This subbasin is located on the inner coastal plain and includes the South River which
converges with the Great Coharie Creek to form the Black River, a major tributary of the Cape
62
Fear River. Land use is primarily agriculture including row crops and concentrated animal
operations.
CFR Basinwide Water Quality Plan lists the following ratings for this subbasin:
Aquatic Life
Not Rated 52.1 freshwater miles
Not Rated
1,454.2 freshwater acres
No Data
242.5 freshwater miles
Recreation
Supporting
No Data
No Data
52.1 freshwater miles
242.5 freshwater miles
1,454.2 freshwater acres
Lower Cape Fear River Program Assessment
Data collection: Since February 1996
Sampling relevance: Below City of Dunn, hog operations in watershed
SR – a slow black water tributary
SR was found to have a poor rating for dissolved oxygen concentrations (Table 3.5.1). The
North Carolina State Standard of 5.0 mg/L was not met 42% of the time and the swampwater
standard of 4.0 mg/L was not 33% of the time. The lowest levels were found in late summer
and early fall (Figure 3.5.1).
SR had a good rating for chlorophyll a, with no samples exceeding the 40 µg/L North Carolina
State Standard (Table 3.5.1).
SR had a fair water quality status for fecal coliform bacteria concentrations, exceeding the NC
State Standard of 200 CFU/100mL in 17% of samples (Table 3.5.1). The highest
concentrations were in August (3,000 CFU/100mL) and May (1200 CFU/100mL).
SR had a good rating for field turbidity, nitrate and total phosphorus (Table 3.5.1).
63
Table 3.5.1 UNCW AEL 2006 evaluation for subbasin 03-06-18
Station
Dissolved Oxygen
Field Turbidity
Chlorophyll a
Fecal Coliform
Nitrate
Total
Phosphorus
SR
P
G
G
F
G
G
Figure 3.5.1 Dissolved oxygen concentrations (mg/L) at SR during 2006. The dashed line
shows the NC State Standard for swampwater of 4.0 mg/L.
64
Aquatic Ecology Laboratory, UNC Wilmington
65
3.6 Cape Fear River Subbasin 03-06-19
Location:
Three main tributaries of Black River near Clinton
Counties:
Sampson
Waterbodies:
Black River, Six Runs Ck., Great Coharie Ck., Little Coharie Ck.
Municipalities:
Clinton, Newton Grove, Warsaw
NPDES Dischargers: 8 @ 6.8 million gallons per day
Concentrated Swine Operations: 374
LCFRP monitoring stations (DWQ #):
LCO (B8610001), GCO (B8604000), 6RC (B8740000)
DWQ monitoring stations: none
GCO
LC
6R
66
This subbasin is located in the coastal plain within Sampson County. Land adjacent to the
Black River is primarily undisturbed forest. There are numerous concentrated swine
operations within this subbasin.
CFR Basinwide Water Quality Plan lists the following ratings for this subbasin:
Aquatic Life
Supporting 71.3 freshwater miles
Not Rated 99.7 freshwater miles
No Data
338.4 freshwater miles
Recreation
Supporting
Not Rated
No Data
153.0 freshwater miles
8.8 freshwater miles
347.6 freshwater miles
Lower Cape Fear River Program Assessment
Data collection: February 1996 to present
Sampling relevance: Many concentrated animal operations (CAOs) within the watershed,
reference areas for point and nonpoint source pollution
GCO - blackwater stream, drains
riparian wetlands
LCO and 6RC had a good rating for dissolved oxygen concentrations, with one measurement
below the NC State Standard of 4.0 mg/L (Table 3.6.1). GCO had a fair rating for dissolved
oxygen concentrations, not meeting the swampwater standard of 4.0 mg/L in 17% of the
samples.
All sites within this subbasin had a good rating for chlorophyll a and field turbidity
concentrations (Table 3.6.1).
GCO had a fair rating for fecal coliform bacteria with 17% of samples exceeding the NC State
human contact standard of 200 CFU/100mL (Table 3.6.1). Both LCO and 6RC had a good
rating for fecal coliform bacteria.
Nitrate levels were rated poor at 6RC and LCO, exceeding 200 µg/L in 67% and 58% of the
samples, respectively (Table 3.6.1, Figure 3.6.1). GCO had a fair rating for nitrate, having
nitrate levels above 200 µg/L in 17% of the samples.
67
Total phosphorus was rated good at 6RC and LCO, and rated fair at GCO with levels above
500 µg/L 17% of the time (Table 3.6.1).
Table 3.6.1 UNCW AEL 2006 evaluation for subbasin 03-06-19
Station
Dissolved Oxygen
Field Turbidity
Chlorophyll a
Fecal Coliform
Nitrate
Total
Phosphorus
6RC
G
G
G
F
P
G
LCO
G
G
G
G
P
G
GCO
F
G
G
G
F
F
Figure 3.6.1 Nitrate concentrations (µg/L) at 6RC, LCO, and GCO during 2006. The dashed
line shows levels considered problematic in black water streams.
1,200
6RC
LCO
GCO
Nitrate-Nitrite (µg/L)
1,000
800
600
400
200
0
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
68
Aquatic Ecology Laboratory, UNC Wilmington
69
Aquatic Ecology Laboratory, UNC Wilmington
70
Aquatic Ecology Laboratory, UNC Wilmington
71
3.7 Cape Fear River Subbasin 03-06-20
Location:
Lower reach of Black River
Counties:
Pender
Waterbodies:
Black River, Colly Creek, Moores Creek
Municipalities:
Town of White Lake, Currie, Atkinson
NPDES Dischargers: 2 at 0.82 million gallons per day
Concentrated Swine Operations: 18
LCFRP monitoring stations (DWQ #):
COL (B8981000), B210 (B9000000), BBT (none)
DWQ monitoring stations: none
B21
COL
BBT
72
This subbasin is located on the coastal plain in Pender County and the land is mostly forested
with some agriculture. The streams in this watershed typically have acidic black waters. The
Black River in this area has been classified as Outstanding Resource Waters (ORW)
(NCDENR DWQ Cape Fear River Basinwide Water Quality Plan, October 2005).
The CFR Basinwide Water Quality Plan lists the following ratings for this subbasin:
Aquatic Life
Supporting
Not Rated
Not Rated
No Data
13.0 freshwater miles
77.9 freshwater miles
576.0 freshwater acres
143.8 freshwater acres
Recreation
Supporting
No Data
No Data
34.9 freshwater miles
199.8 freshwater miles
576.0 freshwater miles
Lower Cape Fear River Program Assessment
Data collection: February 1996 to present
Sampling relevance: Colly Creek is a pristine swamp reference site, B210 and
BBT are middle and lower Black River sites
large
COL – blackwater stream, drains
swamp area, very low pH
B210 - Black River at Hwy 210 bridge
73
All three sites had a good rating for dissolved oxygen when using the NC State swampwater
standard of 4.0 mg/L (Table 3.7.1).
Chlorophyll a and field turbidity concentrations were low for each site within this subbasin and
all sites had a good rating for these parameters (Table 3.7.1).
Fecal coliform bacteria concentrations were generally low with COL rating as good and B210
rating as fair with samples exceeding the NC State standard 17% of the time (Table 3.7.1).
BBT samples were not analyzed for fecal coliform bacteria.
B210 rated good for nitrate concentrations and COL rated fair with samples exceeding the
UNCW AEL recommended stream standard of 200 µg/L 17% of the time. For total phosphorus
B210 and COL rated good (Table 3.7.1). BBT samples were not analyzed for total
phosphorus.
Table 3.7.1 UNCW AEL evaluation for subbasin 03-06-20
Station
Dissolved Oxygen
Field Turbidity
Chlorophyll a
Fecal Coliform
Nitrate
Total
Phosphorus
B210
G
G
G
F
G
G
COL
G
G
G
G
F
G
BBT
G
G
G
na
G
na
74
Aquatic Ecology Laboratory, UNC Wilmington
75
3.8 Cape Fear River Subbasin 03-06-21
Location:
Headwaters of NE Cape Fear River below Mount Olive
Counties:
Duplin, Wayne
Waterbodies:
Northeast Cape Fear River
Municipalities:
Mount Olive
NPDES Dischargers: 6 @ 1.4 million gallons per day
Concentrated Swine Operations: 75
LCFRP monitoring stations (DWQ#):
DWQ monitoring stations:
NC403 (B9090000)
NC403
NC403
This subbasin includes the headwaters of the Northeast Cape Fear River and small tributaries.
This section of the NE Cape Fear River is very slow moving and somewhat congested with
macrophytic growth. Most of the watershed is forested and there is significant agriculture in
the basin.
76
The CFR Basinwide Water Quality Plan lists the following ratings for this subbasin:
Aquatic Life
Supporting 21.7 freshwater miles
Not Rated
38.9 freshwater miles
No Data
84.7 freshwater miles
Recreation
Supporting
No Data
57.3 freshwater miles
88.1 freshwater miles
Lower Cape Fear River Program Assessment
Data collection: June 1997 – present
Sampling relevance: Below Mount Olive Pickle Plant
NC403 - slow moving headwaters of
NE Cape Fear River
NC403 had a poor rating for dissolved oxygen concentrations, not meeting the NC State
swampwater standard of 4.0 mg/L in 33% of the samples (Table 3.8.1, Figure 3.8.1)
NC403 had a good rating for chlorophyll a, yet there is very high aquatic macrophyte biomass
present, often times completely covering and blocking the waterway (Table 3.8.1). As we have
noticed at several of our stations over the years, chlorophyll a, a measurement of
phytoplankton biomass, and often used as an indicator of eutrophic conditions, is not always
adequate to determine problematic conditions with regard to aquatic flora.
Field turbidity was rated as good at NC 403 (Table 3.8.1).
NC403 had a fair rating for fecal coliform bacteria with samples exceeding the NC State
standard for human contact (200 cfu/100 mL) 25% of the time.
High nitrate levels at NC403 led to a poor rating, with nitrate concentrations >200 µg/L for 50%
of the samples (Table 3.8.1, Figure 3.8.1). UNCW AEL researchers are concerned about the
elevated nitrate levels that are periodically found at this site since these levels increase the
likelihood of algal blooms and excessive aquatic macrophyte growth. Total phosphorus
concentrations exceeded the UNCW AEL recommended harmful level on three occasions,
giving this site a fair rating.
77
Table 3.8.1 UNCW AEL 2006 evaluation for subbasin 03-06-21
Station
Dissolved Oxygen
Field Turbidity
Chlorophyll a
Fecal Coliform
Nitrate
Total
Phosphorus
NC403
P
G
G
F
P
F
Figure 3.8.1 Dissolved oxygen (mg/L) and nitrate (µg/L) concentrations at NC403 during
2006. The dashed lines show the NC State DO standard of 4.0 mg/L for swampwater and the
UNCW AEL recommended level of 200 µg/L for nitrate.
78
3.9 Cape Fear River Subbasin 03-06-22
Location:
NE Cape Fear River and tributaries in the vicinity of Kenansville
Counties:
Duplin
Waterbodies:
Northeast Cape Fear River, Rockfish Creek
Municipalities:
Beulaville, Kenansville, Rose Hill and Wallace
NPDES Dischargers: 13 @ 9.9 million gallons per day
Concentrated Swine Operations: 449
LCFRP monitoring stations (DWQ #):
PB (B9130000), GS (B9191000), SAR (B9191500), LRC (9460000)
ROC (B9430000)
DWQ monitoring stations: none
PB
GS
SAR
LRC
ROC
79
Land coverage in this watershed is mostly forested with significant agriculture, including row
crops and a dense concentration of animal operations (poultry and swine).
The CFR Basinwide Water Quality Plans lists the following ratings for this subbasin:
Aquatic Life
Supporting
Not Rated
Impaired
No Data
51.1 freshwater miles
72.1 freshwater miles
50.1 freshwater miles
408.8 freshwater miles
Recreation
Supporting
Not Rated
No Data
73.2 freshwater miles
3.0 freshwater miles
505.9 freshwater miles
Lower Cape Fear River Program Assessment
Data collection: February 1996 to present
Sampling relevance: Below point and non-point source discharges
PB – slow moving swamp-like
stream
ROC - Rockfish Creek below
Wallace
80
All sites in this subbasin were rated using the dissolved oxygen NC State swampwater
standard of 4.0 mg/L. SAR, PB, LRC and ROC all had a good rating (Table 3.9.1). GS had a
poor rating with DO values dropping below the standard 50% of the time.
All sites had a good rating for field turbidity concentrations (Table 3.9.1). Mean levels were
less than 10 NTU for all sites within this subbasin for the 2006.
For chlorophyll a concentrations all sites had a good rating, with no value exceeding the NC
State standard of 40 µg/L (Table 3.9.1).
For fecal coliform bacteria concentrations, using the NC State standard of 200 CFU/100 mL for
human contact, GS had a fair rating (Table 3.9.1). SAR, PB, LRC and ROC all had a poor
rating with 67%, 50%, 33% and 33% of samples above the standard, respectively. Fecal
coliform bacteria concentrations are shown graphically in Figure 3.9.1.
For nitrate, GS had a fair rating (Table 3.9.1). SAR, PB, LRC, and ROC all had a poor rating
with levels exceeding the UNCW AEL standard (200 µg/L) 50%, 50%, 42% and 58% of the
time, respectively. Nitrate levels for SAR, PB, LRC and ROC are shown graphically in Figure
3.9.2.
For total phosphorus all sites had a good rating (Table 3.9.1).
Table 3.9.1 UNCW AEL 2006 evaluation for subbasin 03-06-22
Station
Dissolved Oxygen
Field Turbidity
Chlorophyll a
Fecal Coliform
Nitrate
Total
Phosphorus
SAR
G
G
G
P
P
G
GS
P
G
G
F
F
G
PB
G
G
G
P
P
G
LRC
G
G
G
P
P
G
ROC
G
G
G
P
P
G
81
Figure 3.9.1 Fecal coliform bacteria concentrations (CFU/100mL) during 2006. The dashed
line is the NC State Standard for human contact of 200 cfu/100mL.
Figure 3.9.2 Nitrate-N concentrations (µg/L) at SAR, PB, LRC and ROC during 2006. The
dashed line represents the UNCW AEL suggested threshold for good water quality.
82
Aquatic Ecology Laboratory, UNC Wilmington
83
Aquatic Ecology Laboratory, UNC Wilmington
84
3.10
Cape Fear River Subbasin 03-06-23
Location:
Area near Burgaw and Angola swamp
Counties:
Pender
Waterbodies:
Northeast Cape Fear River,Burgaw Creek
Municipalities:
Burgaw
NPDES Dischargers: 7 @ 3.8 million gallons per day
Concentrated Swine Operations: 52
LCFRP monitoring stations (DWQ #):
ANC (69), BCRR (82), BC117 (83), NCF117 (84), NCF6 (85)
DWQ monitoring stations:
BCRR
NCF117
BC117
ANC
NCF117
NCF6
85
This subbasin is located in the outer coastal plain where many streams are slow flowing
blackwater streams that often dry up during the summer months. Most of the watershed is
forested with some agriculture and increasing human development.
The CFR Basinwide Water Quality Plan lists the following ratings for this subbasin:
Aquatic Life
Supporting
Not Rated
Impaired
Not Rated
No Data
Not Rated
73.8 freshwater miles
36.8 freshwater miles
23.4 freshwater miles
8.3 freshwater miles
233.2 freshwater miles
1.0 saltwater acre
Recreation
Supporting
Supporting
Not Rated
No Data
39.5 freshwater miles
1.0 saltwater acre
11.6 freshwater miles
324.5 freshwater miles
Lower Cape Fear River Program Assessment
Data collection: NCF117 & NCF6 since June 1995, others from February 1996
Sampling relevance: point and non-point source dischargers
ANC - Angola Creek
BC117 - Burgaw Canal at US 117
86
NCF117 - Northeast Cape Fear River at
at US117
This subbasin had extensive dissolved oxygen problems with BC117 and BCRR having a good
rating when using the 4.0 mg/L standard (Table 3.10.1). ANC, NCF6 and SC-CH had a fair
rating with sub-standard samples 25%, 25% and 27% of the time, respectively. NCF117 had a
poor rating, with substandard samples 33% of the time. DO levels for NCF117 are seen in
Figure 3.10.1.
NCF6 and SC-CH had fair ratings for field turbidity, while all other sites were rated good (Table
3.10.1).
All sites in this subbasin had a good rating for chlorophyll a with averages for 2006 well below
the standard of 40 µg/L.
For fecal coliform bacteria, NCF6 had a good rating (Table 3.10.1). ANC, NCF117 and
SC-CH had a fair rating, exceeding the human contact standard 25%, 17% and 27% of the
time, respectively. BC117 and BCRR had a poor rating, exceeding the standard 67% and 75%
of the time. Fecal coliform bacteria concentrations for BCRR and BC117 are shown in Figure
3.10.2.
Nutrient loading of nitrate and total phosphorus was problematic at BC117 which had a poor
rating for both (Table 3.10.1). BC117 had the highest nitrate and tp levels seen in the LCFRP
system. These levels were far above the concentrations known to lead to algal bloom
formation, bacterial increases and increased biochemical oxygen demand (BOD) in blackwater
streams (Mallin et al. 2001, Mallin et al. 2002).
87
Table 3.10.1 UNCW AEL evaluation for subbasin 03-06-23
Station
Dissolved Oxygen
Field Turbidity
Chlorophyll a
Fecal Coliform
Nitrate
Total
Phosphorus
ANC
F
G
G
F
F
G
BC117
G
G
G
P
P
P
BCRR
G
G
G
P
G
G
NCF117
P
G
G
F
G
G
NCF6
F
F
G
G
G
G
SC-CH
F
F
G
F
na
na
Figure 3.10.1 Dissolved oxygen concentrations (mg/L) at NCF117for 2006. The dashed
line shows NC State swampwater standard of 4.0 mg/L.
88
Figure 3.10.2 Fecal coliform bacteria concentrations (CFU/100mL) at BC117 and BCRR
during 2006. The dashed line shows the NC State Standard for human contact waters of 200
CFU/100mL.
89
Aquatic Ecology Laboratory, UNC Wilmington
90
Aquatic Ecology Laboratory, UNC Wilmington
91
3.11
References Cited
Mallin, M.A., L.B. Cahoon, D.C. Parsons and S.H. Ensign. 2001. Effect of nitrogen and
phosphorus loading on plankton in Coastal Plain blackwater streams. Journal of Freshwater
Ecology 16:455-466.
Mallin, M.A., L.B. Cahoon, M.R. McIver and S.H. Ensign. 2002. Seeking science-based
nutrient standards for coastal blackwater stream systems. Report No. 341. Water
Resources Research Institute of the University of North Carolina, Raleigh, N.C.
Mallin, M. A., M.R. McIver, S.H. Ensign and L.B. Cahoon. 2004. Photosynthetic and
heterotrophic impacts of nutrient loading to blackwater streams. Ecological Applications14:
823-838.
NCDENR-DWQ (North Carolina Department of Environment and Natural Resources-Division
of Water Quality), Cape Fear River Basinwide Water Quality Plan. July 2000, Raleigh, N.C.
NCDENR-DWQ (North Carolina Department of Environment and Natural Resources-Division
of Water Quality), Cape Fear River Basinwide Water Quality Plan. October 2005, Raleigh,
N.C.
92