Lower Cape Fear River Program 2018 reportEnvironmental Assessment of the Lower
Cape Fear River System, 2018
By
Michael A. Mallin, Matthew R. McIver and James F. Merritt
August 2019
CMS Report No. 19-02
Center for Marine Science
University of North Carolina Wilmington
Wilmington, N.C. 28409
Executive Summary
Background – Multi-parameter water quality sampling for the Lower Cape Fear River
Program (LCFRP) http://www.uncw.edu/cms/aelab/LCFRP/index.htm, has been
ongoing since June 1995. Scientists from the University of North Carolina Wilmington’s
(UNCW) Aquatic Ecology Laboratory perform the sampling effort. The LCFRP currently
encompasses 32 water sampling stations throughout the lower 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 water quality of the period January - December 2018. 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 a 6th order stream characterized by periodically turbid water containing moderate to high levels of inorganic nutrients. It is fed by two
large 5th order 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, major algal
blooms are normally rare because light is attenuated by water color or turbidity, and flushing in the estuary is usually high (Ensign et al. 2004). During periods of low flow
algal biomass as chlorophyll a increases in the cape Fear River because lower flow
causes settling of more solids and improves light conditions for algal growth.
Periodically major 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 (traditional agriculture and/or industrialized
animal production), and some sites periodically show elevated pollutant loads or effects
(Mallin et al. 2001). This region has been hit by hurricanes several times in the past
three decades and such storms have a marked impact on water quality and organisms.
GenX Issues - During the past three years there has been considerable controversy in
the lower Cape Fear River watershed regarding a family of manufactured chemical
compounds collectively known as GenX. To briefly summarize, DuPont constructed a
facility known as Fayetteville Works near the river downstream of Fayetteville, where it manufactured fluoropolymers since 1971. DuPont manufactured a chemical called
PFOA at Fayetteville Works beginning in 2001, then later stopped its manufacture due
to health concerns surrounding this chemical. They then developed a substitute
chemical called GenX, which they began manufacturing there, along with GenX’s parent
compound, called HFPO-DA fluoride. Both compounds hydrolize in water to a third compound called HFPO-DA, CAS; the toxicity of this group of chemicals is unclear.
Subsequently, DuPont spun-off a company called Chemours, which assumed plant
operations in 2015. In the past few years researchers from US EPA, North Carolina
State University, and the University of North Carolina Wilmington have found HFPO-DA
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and related fluoroethers (which tend to be lumped under the blanket term GenX) in river
water, river sediments, well water near the plant, aquatic organisms, in air samples, and in finished drinking water at the Wilmington water treatment facility, which obtains its
water near Lock and Dam #1. Fayetteville Works is currently trucking their wastewater
out of state for treatment, and lawsuits have been filed against the company from
NCDEQ and Cape Fear River Watch to cease releases and provide financial
compensation. Sampling and analysis of GenX and related compounds is outside of the purview of the scientific staff of the Lower Cape Fear River Program and will not be
discussed in this report.
Summary of water quality data results from 2018 – The major single impact of 2018 was
the arrival of Hurricane Florence, which dumped approximately two feet of water on the region in September 2018 (Plate 1). Biochemical oxygen-demanding materials from
industrial livestock production facilities, wastewater treatment plants, flooded septic
systems and natural debris caused very low dissolved oxygen (DO) concentrations in all
major rivers, but especially in the Northeast Cape Fear River, where DO dropped down
to 0.2 mg/L for weeks at the two LCFRP sites. Massive fish kills occurred in that river as well as the mainstem Cape Fear River (Plate 1). We note, however, that even
before the storm DO concentrations were very low in some areas, often falling below
4.0 mg/L at several blackwater and upper estuary stations.
Year after year 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 are highest at the upper
river stations NC11 and ANC and in the low-to-middle estuary at stations M35 to M18.
Lowest mainstem mean DO levels normally occur at the river and upper estuary
stations NAV, HB, BRR and M61. The Northeast Cape Fear and Black Rivers are classified as blackwater systems because of their tea colored water. The Northeast
Cape Fear and Black Rivers generally have lower DO levels than the mainstem Cape
Fear River.
Dissolved oxygen concentrations in the tributary streams were briefly impacted by the hurricane, but some are chronically bad year-after-year. In 2018 SC-CH and GS were
below standard 27% of the time sampled, and NC403 and AC below standard 18% of
the time. Considering all sites sampled in 2018, we rated 28% as poor for dissolved
oxygen, 16% as fair, and 56% as good.
Annual mean turbidity levels for 2018 were lower than the long-term average in all
estuary stations. Highest mean riverine turbidities were at NC11-DP (26-19 NTU) with
turbidities generally low in the middle to lower estuary. The estuarine stations did not
exceed the estuarine turbidity standard on our sampling trips. Turbidity was
considerably lower in the Northeast Cape Fear River and Black River than in the mainstem river. Turbidity levels were low in the freshwater streams, with all streams
rated as good for 2018.
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Average chlorophyll a concentrations across most sites were low in 2018. The standard
of 40 µg/L was exceeded once at Station SR, and there were several smaller algal blooms as well. We note the highest chlorophyll a levels in the river and estuary
typically occur late spring to late-summer.
High river discharge prevents riverine algal blooms from forming. For 2018, discharge
at Lock and Dam #1 in the May-September growing season (8,590 CFS) was 4X the 2009-2012 low-flow period average of 1,698 CFS. Nuisance cyanobacterial blooms did
not occur in the river and upper estuary in 2018, probably due to the elevated discharge
washing out any algal bloom formation. For the 2018 period UNCW rated 97% of the
stations as good in terms of chlorophyll a.
Fecal bacteria counts in the estuary and at many of the stream stations were elevated in
2018. Almost all of the stream stations in the Northeast Cape Fear and Black River
basins were rated as poor for fecal coliform bacteria counts. However, the main river
and estuary sites were generally in good condition in 2018. For bacterial water quality
overall, 39% of the sites rated as poor, 22% as fair, and 39% as good in 2018.
In addition, by our UNCW standards excessive nitrate and phosphorus concentrations
were problematic at a number of stations.
Plate 1. Hurricane Florence high water marks along the Cape Fear River and Harrison’s
Creek, dead fish at Lock and Dam #1, flooded poultry and swine lagoons (CAFO photos
W.Golder, Audubon), and dead fish at Northeast Cape Fear River boat ramp (photos
M.Mallin unless noted otherwise).
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Table of Contents
Executive Summary…………………………………………………………………………….1
1.0 Introduction...........................................................................………...............…........5
1.1 Site Description................................................………....................................6
1.2 Report Organization………………………………………………………..………7
2.0 Physical, Chemical, and Biological Characteristics of the Lower Cape Fear River
and Estuary………………………………………………..……………………..............11
Physical Parameters..…......................………..........................................……....14
Chemical Parameters…....……..……….........................................................…..18
Biological Parameters.......……….....……......................................................…..21
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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 2018.
The scientific basis of the LCFRP 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
24-year (1995-2018) data base that is available to the public, and is used as a teaching
tool. 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 CarolinaWilmington 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 Environmental Quality, The
NC Division of Marine Fisheries, the US Army Corps of Engineers, technical
representatives from streamside industries, the Cape Fear Public Utility Authority, CapeFear 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. The physical, chemical and biological data are state-certified and submitted to
the US EPA.
Broad-scale monthly water quality sampling at 16 stations in the estuary and lower river
system began in June 1995 (UNCW Aquatic Ecology Laboratory, 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, then lowered to 33 in 2011; currently it stands at 32 water quality stations. 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
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Benthic Ecology Laboratory under various grant-funded projects in the Cape Fear
Estuary. These data are collected and analyzed depending upon the availability of funding. 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 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.
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 9,164 square miles) is the most heavily industrialized in North
Carolina with 203 permitted wastewater discharges with a permitted flow of
approximately 429 million gallons per day, and (as of 2010) over 2.07 million people residing in the basin (NCDENR Basinwide Information Management System (BIMS) &
2010 Census). Approximately 23% of the land use in the watershed is devoted to
agriculture and livestock production (2006 National Land Cover Dataset), 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 time 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 eight 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). We note that after July 2011 sampling was discontinued at estuarine stations
M42 and SPD, per agreement with the North Carolina Division of Water Quality; and in
2012 sampling was expanded at Smith Creek at the Castle Hayne Road bridge (Table
1.1) and initiated at a new site along the South River (SR-WC). 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 (we note that the City of Wilmington and portions of Brunswick County get their
drinking water from the river just upstream of Lock and Dam #1). Station BBT is located on the Black River between Thoroughfare (a stream connecting the Cape Fear and
Black Rivers) 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
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river stations throughout the Cape Fear, Northeast Cape Fear, and Black River
watersheds (Table 1.1; Fig. 1.1; Mallin et al. 2001).
1.2. Report Organization
Section 1 of this report provides a summary and introduction, and Section 2 of this
report presents a detailed overview of physical, chemical, and biological water quality data from the 32 individual stations, and provides tables of raw data as well as figures
showing spatial or temporal trends. LCFRP data are freely available to the public. 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.uncw.edu/cms/aelab/LCFRP/. Additionally, there is an on-line data base. http://lcfrp.uncw.edu/riverdatabase/
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.
Mallin, M.A., S.H. Ensign, M.R. McIver, G.C. Shank and P.K. Fowler. 2001. Demographic, landscape, and meteorological factors controlling the microbial pollution of coastal waters. Hydrobiologia 460:185-193.
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Table 1.1 Description of sampling locations for the Lower Cape Fear River Program, 2018.
Collected by Boat
AEL Station DWR Station #Description Comments County LatLon Stream Class.HUC
NC11 B8360000 Cape Fear River at NC 11 nr East
Arcadia
Below Lock and Dam 1, Represents
water entering lower basin Bladen 34.3969-78.2675 WS-IV Sw 03030005
AC B8450000 Cape Fear River at Neils Eddy
Landing nr Acme
1 mile below IP, DWR ambient
station Columbus 34.3555-78.1794 C Sw 03030005
DP B8465000 Cape Fear River at Intake nr Hooper Hill AT DAK intake, just above confluence with Black R.Brunswick 34.3358-78.0534 C Sw 03030005
BBT Black River below Lyons Thorofare UNCW AEL station Pender 34.3513-78.0490 C Sw ORW+0303005
IC B9030000 Cape Fear River ups Indian Creek nr
Phoenix
Downstream of several point source
discharges Brunswick 34.3021-78.0137 C Sw 0303005
NAV B9050025 Cape Fear River dns of RR bridge at
Navassa
Downstream of several point source
discharges Brunswick 34.2594-77.9877 SC 0303005
HB B9050100 Cape Fear River at S. end of
Horseshoe Bend nr Wilmington
Upstream of confluence with NE
Cape Fear River Brunswick 34.2437-77.9698 SC 0303005
BRR B9790000 Brunswick River dns NC 17 at park
nr Belville Near Belville discharge Brunswick 34.2214-77.9787 SC 03030005
M61B9800000 Cape Fear River at Channel Marker
61 at Wilmington
Downstream of several point source
discharges New Hanover 34.1938-77.9573 SC 03030005
M54B9795000 Cape Fear River at Channel Marker
54
Downstream of several point source
discharges New Hanover 34.1393-77.946 SC 03030005
M35B9850100 Cape Fear River at Channel Marker 35 Upstream of Carolina Beach discharge Brunswick 34.0335-77.937 SC 03030005
M23B9910000 Cape Fear River at Channel Marker
23
Downstream of Carolina Beach
discharge Brunswick 33.9456-77.9696 SA HQW 03030005
M18B9921000 Cape Fear River at Channel Marker
18 Near mouth of Cape Fear River Brunswick 33.913-78.017 SC 03030005
NCF6 B9670000 NE Cape Fear nr Wrightsboro Downstream of several point source
discharges New Hanover 34.3171-77.9538 C Sw 0303007
Collected by Land
6RC B8740000 Six Runs Creek at SR 1003 nr Ingold Upstream of Black River, CAFOs in
watershed Sampson 34.7933-78.3113 C Sw ORW+03030006
LCO B8610001 Little Coharie Creek at SR 1207 nr
Ingold
Upstream of Great Coharie, CAFOs
in watershed Sampson 34.8347-78.3709 C Sw 03030006
GCO B8604000 Great Coharie Creek at SR 1214 nr
Butler Crossroads
Downstream of Clinton, CAFOs in
watershed Sampson 34.9186-78.3887 C Sw 03030006
SR B8470000 South River at US 13 nr CooperDownstream of Dunn Sampson 35.156-78.6401 C Sw 03030006
BRN B8340050 Browns Creek at NC87 nr
Elizabethtown CAFOs in watershed Bladen 34.6136-78.5848 C 03030005
HAM B8340200 Hammond Creek at SR 1704 nr Mt.
Olive CAFOs in watershed Bladen 34.5685-78.5515 C 03030005
COL B8981000 Colly Creek at NC 53 at Colly Pristine area Bladen 34.4641-78.2569 C Sw 03030006
B210B9000000 Black River at NC 210 at Still Bluff 1st bridge upstream of Cape Fear River Pender 34.4312-78.1441 C Sw ORW+03030006
NC403B9090000 NE Cape Fear River at NC 403 nr
Williams
Downstream of Mt. Olive Pickle,
CAFOs in watershed Duplin 35.1784-77.9807 C Sw 0303007
PB B9130000 Panther Branch (Creek) nr Faison Downstream of Bay Valley Foods Duplin 35.1345-78.1363 C Sw 0303007
GS B9191000 Goshen Swamp at NC 11 and NC 903
nr Kornegay CAFOs in watershed Duplin 35.0281-77.8516 C Sw 0303007
SAR B9191500 NE Cape Fear River SR 1700 nr
Sarecta
Downstream of several point source
discharges Duplin 34.9801-77.8622 C Sw 0303007
ROC B9430000 Rockfish Creek at US 117 nr WallaceUpstream of Wallace discharge Duplin 34.7168-77.9795 C Sw 0303007
LRC B9460000 Little Rockfish Creek at NC 11 nr
Wallace DWR Benthic station Duplin 34.7224-77.9814 C Sw 0303007
ANC B9490000 Angola Creek at NC 53 nr Maple HillDWR Benthic station Pender 34.6562-77.7351 C Sw 0303007
SR WC B8920000 South River at SR 1007
(Wildcat/Ennis Bridge Road)Upstream of Black River Sampson 34.6402-78.3116 C Sw ORW+03030006
NCF117B9580000 NE Cape Fear River at US 117 at
Castle Hayne
DWR ambient station, Downstream
of point source discharges New Hanover 34.3637-77.8965 B Sw 0303007
SC-CH B9720000 Smith Creek at US 117 and NC 133 at
Wilmington
Urban runoff, Downstream of
Wilmington Northside WWTP New Hanover 34.2586-77.9391 C Sw 0303007
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Figure 1.1. Map of the Lower Cape Fear River system and the LCFRP sampling stations.
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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 2018 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, and metals as requested by
NCDEQ. Selected biological parameters including fecal coliform bacteria or Enterococcus
bacteria and chlorophyll a were examined.
2.2 - Materials and Methods
Samples and field parameters collected for the estuarine stations of the Cape Fear River
(NAV down through M18) were gathered (when possible) 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 Environmental Quality
inspect UNCW laboratory procedures and periodically accompany field teams to verify
proper procedures are followed. By agreement with N.C. Division of Environmental Quality, changes have periodically occurred in the sampling regime. Station SCCH (lower
Smith Creek) was added October 2004; sampling was discontinued at Stations M42 and
SPD (June 2011); sampling at Stations BCRR and BC117 was discontinued (December
2012); sampling was added at Station SR-WC on the South River (March 2013); and
sampling was discontinued at Station LVC2 (July 2015). Special sampling for dissolved metals was initiated at selected stations by NCDEQ in 2015 and is ongoing.
Physical Parameters
Water Temperature, pH, Dissolved Oxygen, Turbidity, Light, Salinity, Conductivity
Field parameters other than light attenuation were measured at each site using a YSI
6920/650 MDS or YSI EXO3. Each parameter is measured with individual probes on the
sonde. At stations sampled by boat (see Table 1.1) physical parameters were measured
10
at 0.1 m and at the bottom (up to 12 m); only surface data are reported within.
Occasionally, high flow prohibited the sonde from reaching the actual bottom and measurements were taken as deep as possible. At the terrestrially sampled stations (i.e.
from bridges or docks) the physical parameters were measured at a depth of 0.1 m. The
Aquatic Ecology Laboratory at the UNCW CMS is State-certified by the N.C. Division of
Environmental Quality to perform field parameter measurements. The light attenuation
coefficient k was determined from data collected on-site using vertical profiles obtained by a Li-Cor LI-1000 integrator interfaced with a Li-Cor LI-193S spherical quantum sensor.
Chemical Parameters
Nutrients
A local State-certified analytical laboratory was contracted to conduct all chemical
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-phospho-molybdate 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 / Enterococcus
Fecal coliform bacteria were analyzed by 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. After August 2011 the fecal coliform analysis was changed to Enterococcus bacteria in the estuarine stations downstream of NAV and HB (Stations
BRR, M61, M35, M23 and M18).
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Chlorophyll a
The analytical method used to measure chlorophyll a is described in Welschmeyer (1994)
and US EPA (1997) and was performed by UNCW Aquatic Ecology Laboratory personnel.
Chlorophyll a concentrations were determined utilizing 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 was
immersed in 10 mL of 90% acetone for 24 hours, which extracts the chlorophyll a into
solution. Chlorophyll a concentration of each solution was 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. The Aquatic Ecology Laboratory at the CMS is State-certified by the N.C. Division of
Environmental Quality for the analysis of chlorophyll a (chlorophyll at three LCFRP stations
are required by NCDEQ to be analyzed by state-certified methods); the rest of the large
amount of chlorophyll a data presented here were not State-certified.
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 for several years. BOD analysis was stopped in August 2015 due to
insufficient program funding; previous BOD data are available from LCFRP.
Parameter Method NC DEQ Certified
Water Temperature SM 2550B-2000 Yes
Dissolved Oxygen SM 4500O G-2001 Yes
pH SM 4500 H B-2000 Yes
Specific Conductivity SM 2510 B-1997 Yes
Lab Turbidity SM 2130 B-2001 Yes
Field Turbidity SM 2130 B-2001 No
Chlorophyll a EPA 445.0 Rev. 1.2 Yes
Biochemical Oxygen Demand SM 5210 B-2001 No
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Parameter Method NC DEQ Certified
Total Nitrogen By addition
Nitrate + Nitrite EPA 353.2 Rev 2.0 1993 Yes
Total Kjeldahl Nitrogen EPA 351.2 Rev 2.0 1993 Yes
Ammonia Nitrogen EPA 350.1 Rev 2.0 1993 Yes
Total Phosphorus SM 4500 P E-1999 Yes
Orthophosphate EPA 365.5 No
Fecal Coliform SM 9222 D-1997 Yes
Enterococcus Enterolert IDEXX Yes
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 2018. Discussion of the
data focuses both on the river channel stations and stream stations, which sometimes
reflect poorer water quality than the channel stations. 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. As noted, the Cape Fear region experienced major impacts from Hurricane Florence in 2018; therefore this report reflects
the impacts in fall; note that September sampling was missing from some stations due to
lack of access.
Physical Parameters
Water temperature
Water temperatures at all stations ranged from 3.1 to 31.3oC, and individual station annual averages ranged from 15.2 to 19.1oC (Table 2.1). Highest temperatures occurred during
July and lowest temperatures during January and 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 (NAV through M18; also NCF6 in the Northeast Cape
Fear River) ranged from 0.0 to 31.4 practical salinity units (psu) and station annual means
ranged from 0.1 to 22.3 psu (Table 2.2). Lowest salinities occurred in late spring and again in October following the heavy rains from the hurricane. As such, the annual mean
salinities for 2018 were lower compared with the twenty-one year average for 1995-2017
(Figure 2.1). Two stream stations, NC403 and PB, had occasional oligohaline conditions
due to discharges from pickle production facilities. SC-CH is a blackwater tidal creek that
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enters the Northeast Cape Fear River upstream of Wilmington and salinity there ranged
from 0.1 to 2.4 psu.
Conductivity
Conductivity at the estuarine stations ranged from 0.09 to 48.16 mS/cm and from 0.05 to
4.56 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. Stations PB and NC403 are below industrial discharges, and
often have elevated conductivity. Smith Creek (SC-CH) is an estuarine tidal creek and the
conductivity values reflect this (Table 2.3).
pH
System pH values ranged from 3.5 to 8.1 and station annual means ranged from 4.1 to 8.0
(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 in this wetland-rich rural
watershed.
Dissolved Oxygen
Dissolved oxygen (DO) problems have long been 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; 2001; 2002; 2004; 2005; 2006). There is an annual 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). 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. Surface concentrations for all sites in 2018 ranged
from 0.2 to 13.6 mg/L and station annual means ranged from 5.8 to 8.3 mg/L (Table 2.5).
Overall, average dissolved oxygen levels were mixed in 2018 compared with the long-term average (Fig. 2.2). River dissolved oxygen levels were low during the summer (Table 2.5),
often falling below the state standard of 5.0 mg/L at several river and upper estuary
stations.
While DO concentrations were already low in summer the September arrival of Hurricane Florence brought approximately two feet of rain to the area, caused a massive BOD load
from animal waste, sewage and natural swamp organic matter to drop DO lower than
usual in October. Hurricane Florence led to the release of many millions of gallons of
untreated or partially treated sewage due to system flooding, power failures, generator
14
damage and pump station failures. According to reported data, Fayetteville had > 7.6
million gallons reaching surface waters, Wilmington had to reroute 5.25 million gallons into the river, and Carolina Beach had to discharge 17.2 million gallons to the estuary.
According to industry self-reporting, 49 swine waste lagoons serving concentrated animal
feeding operations (CAFOs) either breached, overtopped or were inundated by
floodwaters, and another 47 lagoons were possibly compromised by high freeboard in the
lagoons. Many thousands of acres of swine sprayfields and poultry CAFO litterfields were inundated by floodwaters as well. The Northeast Cape Fear River stations (NCF117 and
BCF6) were particularly hard hit by the BOD load, with DO dropping to 0.2 mg/L for several
weeks. This caused massive fish kills in the system (see front cover) including
endangered sturgeon
Overall for the year, stations M61 and M54 were below 5.0 mg/L on 45% or more of
occasions sampled, NAV was below on 36% of occasions sampled, and HB and M35
below standard 27% of th etime. Based on number of occasions the river stations were
below 5 mg/L UNCW rated NAV, HB, M61, M54, M35 and BRR as poor for 2018; the lower
estuary stations were rated as good. On a year-to-year basis, discharge of 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, helps to decrease oxygen in
the lower river and upper estuary. Additionally, algal blooms periodically form behind Lock
and Dam #1 (including the blue-green algal blooms from 2009-2012), and the chlorophyll a
they produce is strongly correlated with BOD at Station NC11 (Mallin et al. 2006); thus algal blooms do contribute to lower DO in the river. As the water reaches the lower
estuary higher algal productivity, mixing and ocean dilution help alleviate oxygen problems.
We note that due to the hurricane, DO conditions in the lower river and estuary in 2018
were worse than 2017.
The hurricane impacted the tributary stream stations in October, but DO levels recovered
in November. Tributary Stations SC-CH and GS were below 4.0 mg/L on 27% of
occasions sampled (rated poor), and NC403 and ANC 18% (rated fair) most others were in
the good category (Table 2.5). Some hypoxia can be attributed to low summer 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. 2001; 2002; 2004). Hypoxia is thus a continuing problem,
with 32% of the sites impacted in 2017.
Field Turbidity
Field turbidity levels ranged from 0 to 87 Nephelometric turbidity units (NTU) and station
annual means ranged from 3 to 26 NTU (Table 2.6). The State standard for estuarine
turbidity is 25 NTU. Highest mean turbidities were at NC11-DP (26-19 NTU), with
turbidities generally low in the middle to lower estuary (Figure 2.3). The estuarine stations did not exceed the estuarine turbidity standard on our 2018 sampling trips. As in the
previous year, mean turbidity levels for 2018 were well below the long-term average at all
estuary sites (Fig. 2.3). Turbidity was considerably lower in the blackwater tributaries
(Northeast Cape Fear River and Black River) than in the mainstem river. Average turbidity
15
levels were low in the freshwater streams. The State standard for freshwater turbidity is 50
NTU.
Note: In addition to the laboratory-analyzed turbidity that are required by NCDWQ for
seven locations, 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 State-certified 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 (TSS)
An altered monitoring plan was developed for the LCFRP in September 2011. These
changes were suggested by the NC Division of Environmental Quality (then DWQ). NCDEQ suggested the LCFRP stop monitoring TSS at Stations ANC, GS, 6RC, LCO, SR,
BRN, HAM, COL, SR-WC and monitor turbidity instead. DWQ believed turbidity would be
more useful than TSS in evaluating water quality at these stations because there are water
quality standards for turbidity. TSS is used by the DWQ NPDES Unit to evaluate
discharges. No LCFRP subscribers discharge in these areas.
Total suspended solid (TSS) values system wide ranged from 1.3 to 85.0 mg/L with station
annual means from 2.3 to 27.3 mg/L (Table 2.7). The overall highest river values were at NC11 and AC. In the stream stations TSS was generally considerably lower than the river
and estuary. 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. While there
is no NC ambient standard for TSS, many years of data from the lower Cape Fear
watershed indicates that 25 mg/L can be considered elevated (reached on a few occasions
in the 2018 data). The fine silt and clay in the upper to middle estuary sediments are most likely derived from the Piedmont and carried downstream to the estuary, while the
sediments in the lowest portion of the estuary are marine-derived sands (Benedetti et al.
2006).
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 (reduced through absorbance or reflection) in the water column. River and estuary light attenuation coefficients ranged from 0.74 to 7.10/m and station annual means ranged from 2.23 at M18 to 3.98 at NAV (Table 2.8). Elevated mean and median light
16
attenuation occurred from NC11 river downstream to M54 in the estuary (Table 2.8). In
the Cape Fear system, light is attenuated by both turbidity and water color.
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 generally high 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; Dubbs and Whalen 2008).
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 50 (detection limit) to 6,480 µg/L (at ROC) and station annual
means ranged from 657 to 2,804 µg/L (at NC403; Table 2.9). Previous research (Mallin et
al. 1999) has shown a positive correlation between river flow and TN in the Cape Fear
system. In the main river total nitrogen concentrations were highest and relatively similar between NC11 and AC, then declining 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 denitrification. The highest median TN
value at the stream stations was at NC403 with 2,540 µg/L; other elevated TN values were
seen at ANC, ROC, 6RC and PB.
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 10 (detection limit)
to 4,430 µg/L (at PB) and station annual means ranged from 24 to 1,858 µg/L (at NC403;
Table 2.10). The highest average riverine nitrate levels were at NC11, AC and DP (734-
660 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. 2005). Nitrate can
limit phytoplankton production in the lower estuary in summer (Mallin et al. 1999). The blackwater rivers carried lower concentrations of nitrate compared to the mainstem Cape
Fear stations; i.e. the Northeast Cape Fear River (NCF117 mean = 302 µg/L) and the
Black River (B210 = 327 µg/L). Lowest river nitrate occurred during late spring and early
summer. In general, average concentrations in 2018 for the mainstem river were lower than those of the average from 1995-2017 (Fig. 2.4); although nitrate concentrations post-
hurricane (October and November were elevated in the rivers compared with pre-storm
values (Table 2.10).
17
Several stream stations showed high levels of nitrate on occasion including NC403, PB, ROC and 6RC. ROC and 6RC primarily receive non-point agricultural or animal waste
drainage, while point sources contribute to NC403 and PB. In general, the stream stations
showed elevated nitrate in late fall and early winter following the massive runoff from the
storm in September. 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 200
to 500 µg/L as N (Mallin et al. 1998; Mallin et al. 2001; Mallin et al. 2002, Mallin et al. 2004). Thus, we conservatively consider nitrate concentrations exceeding 500 µg/L as N
in Cape Fear watershed streams to be potentially problematic to the stream’s
environmental health.
Ammonium/ammonia
Ammonium concentrations ranged from 10 (detection limit) to 1,240 µg/L and station
annual means ranged from 53 to 237 µg/L (Table 2.11). River areas with the highest
mean ammonium levels this monitoring period included AC and DP, which are downstream of a pulp mill discharge, and M54 in the upper estuary near the Wilmington
Southside Wastewater Treatment Plant. At the stream stations 2018 continued to be
unusual in that Colly Creek (COL) showed multiple occasions of high ammonium. This
station is in a wetland-rich watershed that has a low level of human development. Most
previous years have showed generally low levels of ammonium; however, beginning in 2005 a few unusual peaks began to occur, which increased in magnitude and frequency
after 2012, particularly in 2016, 2017 and 2018 (Fig. 2.6). We do not have a solid
explanation for this increase in ammonium. We are aware that White Lake, located in the
upper Colly Creek watershed has had increasing problems with eutrophication (NC DEQ
2017), with nearby upper groundwater and surface runoff showing elevated nutrient concentrations (especially ammonium; potentially from failing local sewage infrastructure in
the densely-developed area immediately surrounding the lake). General nutrient
concentrations in the lake have been increasing over time as well (NCDEQ 2017). Thus,
possibly ammonium-rich drainage from this area has made its way down to the COL
station. Additional areas with periodic elevated ammonium in 2018 included ANC, LRC and PB (Table 2.11).
Total Kjeldahl Nitrogen
Total Kjeldahl Nitrogen (TKN) is a measure of the total concentration of organic nitrogen
plus ammonium. TKN ranged from 50 (detection limit) to 4,200 µg/L and station annual
means ranged from 468 to 1,464 µg/L (Table 2.12). TKN concentration decreases ocean-
ward through the estuary, likely due to ocean dilution and food chain uptake of nitrogen.
Stations with highest median concentrations included ANC and COL. As with ammonium,
18
upper groundwater in the White Lake drainage contained high TKN (NC DEQ 2017), some
of which may have gone downstream.
Total Phosphorus
Total phosphorus (TP) concentrations ranged from 10 (detection limit) to 1,390 µg/L (at
ROC) and station annual means ranged from 45 to 305 µg/L (ROC; Table 2.13). For the
mainstem and upper estuary, average TP for 2018 was higher than the 1995-2017
average; at all sites downstream of AC (Figure 2.6). In the river TP was highest at the
upper riverine channel stations NC11, AC and DP and declined downstream into the
estuary; there was an increase at M61, however. Some of this decline is attributable to the settling of phosphorus-bearing suspended sediments, yet incorporation of phosphorus into
bacteria and algae is also responsible.
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 500 µg/L led to significant
increases in bacterial counts, as well as significant increases in BOD over control. Thus,
we consider concentrations of phosphorus above 500 µg/L to be potentially problematic to
blackwater streams (Mallin et al. 1998; 2004). Streams periodically exceeding this critical concentration included ROC, GCO and ANC; NC403 and PB also yielded some high
values. Stations NC403 and PB are downstream of an industrial wastewater discharge,
while ROC, GCO and ANC are in non-point agricultural areas.
Orthophosphate
Orthophosphate ranged from 5 to 480 µg/L and station annual means ranged from 6 to
170 µg/L (Table 2.14). Much of the main river orthophosphate load is imported into the
Lower Cape Fear system from upstream areas, as NC11 or AC typically have high levels; there are also inputs of orthophosphate from the paper mill above AC (Table 2.140.
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 lower
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).
ROC, ANC and GCO had the highest stream station orthophosphate concentrations. All of
those sites are in non-point source areas.
19
Chemical Parameters - EPA Priority Pollutant Metals
The LCFRP had previously sampled for water column metals (EPA Priority Pollutant
Metals) on a bimonthly basis. However, as of 2007 this requirement was suspended by
the NC Division of Water Quality and these data are no longer collected by the LCFRP.
Revised metals sampling (dissolved, not total metals) was re-initiated in late 2015 and
continued periodically upon request from NCDEQ. Results showed that for both stations sampled (M35 and M23) concentrations of As, Cd, Cr, Cu, Pb, Ni and Zn were below
detection limits on all sampling occasions. Iron (Fe) concentrations were measurable but
not at harmful levels. There was one metals sample collected in December 2018 at IC and
NAV, with no unusual or adversely high concentrations. Two more samples are scheduled
for those locations for 2019.
Biological Parameters
Chlorophyll a
During this monitoring period, chlorophyll a was low in river and estuary locations (Table
2.15). The state standard was not exceeded in the river or estuary samples in 2018. We
note that at the upper site NC11 it has been demonstrated that chlorophyll a biomass is
significantly correlated with biochemical oxygen demand (BOD5 – Mallin et al. 2006).
System wide, chlorophyll a ranged from undetectable to 43 µg/L, and station annual
means ranged from 1-13 µg/L, generally low because of high river discharge in 2018 (see
below). Production of chlorophyll a biomass is usually low to moderate in the rivers and
estuary primarily because of light limitation by turbidity in the mainstem (Dubbs and
Whalen 2008) and high organic color and low inorganic nutrients in the blackwater tributary rivers.
Spatially, along the river mainstem highest values are normally found in the mid-to-lower
estuary stations because light becomes more available downstream of the estuarine
turbidity maximum (Fig. 2.7). On average, 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. However, under lower-than-average flows there is generally clearer water
through less suspended material and less blackwater swamp inputs. We note that there
were a series of problematic cyanobacterial (blue-green algae) blooms of Microcyctis aeruginosa on the mainstem river in summers of 2009-2012 (Isaacs et al. 2014). For the
growing season May-September, long-term (1995-2018) average monthly flow at Lock and
Dam #1 was approximately 3,631 CFS; however, for cyanobacterial bloom years 2009-
2012 the growing season average flow was 1,698 CFS (USGS data;
(http://nc.water.usgs.gov/realtime/real_time_cape_fear.html). For 2018, discharge in May-September (due to the hurricane) was more than triple the 2009-2012 average at 8,590
CFS. Nuisance cyanobacterial blooms did not occur in the river and upper estuary in
2018.
20
The blooms in 2009-2012 all occurred when average river discharge for May-September
was below 1,900 CFS. Algal bloom formation was suppressed by elevated river flow in 2013-2014, 2016 and 2018, but flow in 2015 was well within the range when blooms can
occur. Clearly other factors are at work in bloom formation.
Phytoplankton blooms occasionally occur at the stream stations, with a few occurring at
various months in 2018 (Table 2.15). These streams are generally shallow, so vertical mixing does not carry phytoplankton cells down below the critical depth where respiration
exceeds photosynthesis. In areas where the forest canopy opens up large blooms can
occur. When blooms occur in blackwater streams 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; 2006; 2015). A stream station bloom exceeding the state standard of 40 µg/L occurred on one occasion at Station SR, and
lesser blooms occurred on occasion at PB, N403, ROC, ANC and GS (Table 2.15).
Biochemical Oxygen Demand
Beginning in 2015 samples for BOD5 and BOD20 are no longer collected for the program
due to insufficient funds.
Fecal Coliform Bacteria/ Enterococcus bacteria
Fecal coliform (FC) bacterial counts ranged from 5 to 60,000 CFU/100 mL (60,000 is the
laboratory maximum) and station annual geometric means ranged from 12 to 340 CFU/100
mL (Table 2.17). The state human contact standard (200 CFU/100 mL) was exceeded in
the mainstem river on a few occasions in 2018 (Table 2.17). The Northeast Cape Fear
River showed unusually high fecal coliform counts in 2018, with NCF6 and NCF117 both exceeding the standard on three occasions. During 2018 some stream stations showed
very high fecal coliform pollution levels. HAM exceeded 200 CFU/100 mL 73% of the time
sampled; ROC 64%, BRN 55%, PB and LCO 46%, NC403 and SCH 36% and ANC and
LRC 27% of the time sampled. One notably excessive count of 60,000 CFU/100 mL
occurred at PB in July, while most other counts stayed below 2,000 CFU/100 mL. NC403 and PB are located below point source discharges and the other sites are primarily
influenced by non-point source pollution. Beginning in 2015 but especially in 2017 COL
had a number of unusually high fecal coliform counts; but counts were much lesser in 2018
(Fig. 2.5). Overall, 2018 was comparatively better than previous years, despite the
hurricane. In fact, at most chronically polluted sites high counts were in spring and summer months before the hurricane, whereas the high counts immediately after the
hurricane decreased rapidly after October (Table 2.16; Fig. 2.8). We speculate that the
extreme rainfall and river discharge (25,600 CFS at Lock and Dam #1 in September)
diluted fecal bacteria counts, despite the CAFO accidents and sewage discharges.
Enterococcus counts were initiated in the estuary in mid-2011, as this test is now the
standard used by North Carolina regulators for swimming in salt waters. Sites covered by
this test include BRR, M61, M54, M35, M23 and M18. The State has a single-sample level
for Tier II swimming areas in which the enterococci level in a Tier II swimming area shall
21
not exceed a single sample of 276 enterococci per 100 milliliter of water (15A NCAC 18A
.3402); the LCFRP is using this standard for the Cape Fear estuary samples in our rating system. As such, in 2018 this standard was not exceeded in the estuary samples.
Geometric mean enterococcus counts for 2018 were lower than those of the 2012-2017
period for the lower Cape Fear Estuary (Fig. 2.8). Overall, elevated fecal coliform and
Enterococcus counts are problematic in this system, with 61% of the stations rated as Fair
or Poor in 2018 (although that was an improvement from 2017).
2.4 - References Cited
APHA. 1995. Standard Methods for the Examination of Water and Wastewater, 19th ed.
American Public Health Association, Washington, D.C. Benedetti, M.M., M.J. Raber, M.S. Smith and L.A. Leonard. 2006. Mineralogical indicators of alluvial sediment sources in the Cape Fear River basin, North Carolina. Physical Geography 27:258-281. Dubbs, L. L. and S.C. Whalen. 2008. Light-nutrient influences on biomass, photosynthetic potential and composition of suspended algal assemblages in the middle Cape Fear River, USA. International Review of Hydrobiology 93:711-730. 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. Isaacs, J.D., W.K. Strangman, M.A. Mallin, M.R. McIver, and J.L.C. Wright. 2014. Microcystins and two new micropeptin cyanopeptides produced by unprecedented Microcystis aeruginosa blooms in North Carolina’s Cape Fear River. Harmful Algae 31:82-86. 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.
22
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. 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 Applications 14:823-838. Mallin, M.A., L.B. Cahoon and M.J. Durako. 2005. 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., V.L. Johnson, S.H. Ensign and T.A. MacPherson. 2006. Factors contributing
to hypoxia in rivers, lakes and streams. Limnology and Oceanography 51:690-701.
Mallin, M.A., M.R. McIver, A.R. Robuck and A.K. Dickens. 2015. Industrial swine and poultry production causes chronic nutrient and fecal microbial stream pollution. Water, Air and Soil Pollution 226:407, DOI 10.1007/s11270-015-2669-y.
NCDEQ 2017. 2017 White Lake Water Quality Investigation, White Lake, Bladen County
(Cape Fear Basin). North Carolina Department of Environmental Quality, Division of
Water Resources.
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.
23
Table 2.1 Water temperature (oC) during 2018 at the Lower Cape Fear River Program stations.
NAV HB BRR M61 M54 M35 M23 M18 NC11 AC DP BBT IC NCF6
JAN 3.0 3.7 4.0 4.0 3.9 4.1 4.2 4.7 JAN 4.4 5.1 4.4 2.4 3.2 4.3
FEB 7.9 8.5 8.5 8.8 9.4 9.9 9.3 9.4 FEB 8.4 8.1 8.0 8.0 8.2 8.5
MAR 12.4 13.0 12.1 12.8 13.0 13.6 13.1 12.8 MAR 11.8 11.9 11.8 13.1 12.3 13.3
APR 15.9 16.0 16.0 16.6 16.6 16.1 15.7 15.1 APR 15.8 16.5 16.3 16.8 16.2 16.7
MAY 25.4 25.7 25.7 25.3 25.4 25.4 25.8 25.3 MAY 17.9 17.9 18.1 19.8 20.3 20.1
JUN 27.7 26.7 29.2 27.8 28.6 28.0 27.7 27.2 JUN 27.2 27.0 27.3 26.2 27.1 26.0
JUL 30.5 31.3 31.0 31.0 30.7 30.8 30.1 29.9 JUL 28.8 28.9 29.3 28.9 28.7 27.5
AUG 27.7 27.8 28.1 27.6 27.9 28.2 28.7 28.6 AUG 27.1 27.3 27.2 27.3 27.4 26.3
SEP SEP 29.4 29.4 29.2 28.6 29.0 29.4
OCT 22.4 22.5 22.6 23.6 23.7 24.4 25.3 25.5 OCT 25.1 25.1 25.1 25.5 25.4 27.7
NOV 15.9 16.5 16.2 17.1 17.1 17.3 17.2 19.2 NOV 17.0 16.9 17.0 17.5 17.6 18.5
DEC 8.5 8.7 8.3 9.0 9.0 9.9 9.9 12.5 DEC 8.8 8.9 9.0 9.2 9.2 10.5
mean 17.9 18.2 18.3 18.5 18.7 18.9 18.8 19.1 mean 18.5 18.6 18.6 18.6 18.7 19.1
std dev 9.4 9.2 9.5 9.1 9.1 9.0 9.1 8.7 std dev 8.9 8.8 8.9 9.0 9.0 8.5
median 15.9 16.5 16.2 17.1 17.1 17.3 17.2 19.2 median 17.5 17.4 17.6 18.7 19.0 19.3
max 30.5 31.3 31.0 31.0 30.7 30.8 30.1 29.9 max 29.4 29.4 29.3 28.9 29.0 29.4
min 3.0 3.7 4.0 4.0 3.9 4.1 4.2 4.7 min 4.4 5.1 4.4 2.4 3.2 4.3
ANC SAR GS NC403 PB LRC ROC NCF117 SC-CH B210 COL SRWC 6RC LCO GCO SR BRN HAM
JAN 5.7 3.1 4.5 3.6 3.2 5.2 4.2 8.1 7.5 JAN 6.8 5.5 7.4 7.3 6.5 5.0 5.8 6.2 6.6
FEB 11.2 12.0 11.6 11.2 10.3 11.7 12.1 9.1 11.1 FEB 12.8 13.4 12.9 14.6 14.3 12.7 11.8 12.8 12.0
MAR 9.2 6.2 8.6 7.3 7.0 9.1 8.3 11.2 11.5 MAR 10.8 10.8 10.8 11.3 11.4 11.0 13.3 16.7 15.2
APR 12.6 11.9 13.4 13.2 13.3 13.8 12.3 16.8 16.4 APR 18.1 17.2 16.1 16.4 16.5 17.0 17.4 17.8 17.1
MAY 18.6 18.4 21.0 20.2 18.0 18.6 17.3 18.7 19.9 MAY 20.0 18.3 19.9 19.0 19.9 20.3 20.5 20.0 19.4
JUN 23.7 24.1 25.2 24.2 24.6 24.8 23.1 25.0 25.5 JUN 24.7 23.7 24.0 24.1 24.2 25.0 25.6 24.5 24.1
JUL 26.0 26.8 26.1 26.8 27.3 26.6 25.8 28.5 28.1 JUL 27.0 24.8 25.3 25.2 25.4 26.4 27.7 25.2 24.5
AUG 26.0 25.8 26.0 26.2 26.8 24.9 25.6 26.8 28.2 AUG 27.0 27.6 25.6 25.5 25.4 25.8 26.9 26.3 26.1
SEP SEP
OCT 21.2 24.9 26.6 25.3 24.3 25.3 24.1 25.2 25.8 OCT 21.8 20.5 20.8 20.9 20.8 20.0 19.2 14.3 12.4
NOV 8.6 5.3 6.6 7.3 6.1 7.9 6.8 9.6 10.7 NOV 17.0 18.0 16.2 17.2 17.1 18.0 18.3 19.7 18.6
DEC 9.5 8.3 9.2 9.6 7.7 10.2 9.7 10.7 10.9 DEC 10.7 12.0 10.6 11.6 11.9 7.2 7.2 7.9 7.0
mean 15.7 15.2 16.3 15.9 15.3 16.2 15.4 17.2 17.8 mean 17.9 17.4 17.2 17.6 17.6 17.1 17.6 17.4 16.6
std dev 7.6 9.1 8.8 8.8 9.2 8.1 8.1 7.9 8.0 std dev 7.0 6.6 6.4 6.1 6.2 7.4 7.5 6.7 6.7
median 12.6 12.0 13.4 13.2 13.3 13.8 12.3 16.8 16.4 median 18.1 18.0 16.2 17.2 17.1 18.0 18.3 17.8 17.1
max 26.0 26.8 26.6 26.8 27.3 26.6 25.8 28.5 28.2 max 27.0 27.6 25.6 25.5 25.4 26.4 27.7 26.3 26.1
min 5.7 3.1 4.5 3.6 3.2 5.2 4.2 8.1 7.5 min 6.8 5.5 7.4 7.3 6.5 5.0 5.8 6.2 6.6
24
Table 2.2 Salinity (psu) during 2018 at the Lower Cape Fear River Program estuarine stations.
NAV HB BRR M61 M54 M35 M23 M18 NCF6 SC-CH
JAN 0.3 3.1 6.3 9.9 11.2 16.4 23.5 26.4 0.1 0.8
FEB 0.1 0.1 0.1 0.8 2.7 8.3 24.2 27.7 0.2 0.1
MAR 0.1 0.6 0.5 3.9 6.3 14.8 21.1 31.4 0.5 1.4
APR 0.1 0.1 2.0 6.0 9.4 14.3 20.0 23.4 0.1 1.0
MAY 0.1 0.1 0.1 0.2 1.8 5.5 13.0 18.6 0.0 0.1
JUN 0.1 0.0 0.1 0.2 1.0 3.1 9.1 16.4 0.0 0.1
JUL 0.3 0.7 2.5 5.9 8.0 13.7 22.4 26.1 0.1 2.4
AUG 0.0 0.0 0.0 0.0 0.1 1.3 7.0 8.2 0.0 0.1
SEP
OCT 0.0 0.0 0.0 1.0 1.2 3.0 8.1 10.7 0.0 0.1
NOV 0.1 0.6 0.2 2.1 4.8 10.8 16.8 29.6 0.5 0.1
DEC 0.0 0.1 0.1 1.1 3.0 8.7 11.9 26.5 0.0 0.1
mean 0.1 0.5 1.1 2.8 4.5 9.1 16.1 22.3 0.1 0.6
std dev 0.1 0.9 1.9 3.2 3.7 5.3 6.5 7.7 0.2 0.8
median 0.1 0.1 0.1 1.1 3.0 8.7 16.8 26.1 0.1 0.1
max 0.3 3.1 6.3 9.9 11.2 16.4 24.2 31.4 0.5 2.4
min 0.0 0.0 0.0 0.0 0.1 1.3 7.0 8.2 0.0 0.1
25
0
5
10
15
20
25
30
NAV HB BRR M61 M54 M35 M23 M18 NCF6 SC-CH
Sa
l
i
n
t
y
(
P
S
U
)
Figure 2.1 Salinity at the Lower Cape Fear River Program estuarine stations
1995-2017 versus 2018.
1995-2017
2018
26
Table 2.3 Conductivity (mS/cm) during 2018 at the Lower Cape Fear River Program stations.
NAV HB BRR M61 M54 M35 M23 M18 NC11 AC DP BBT IC NCF6
JAN 0.67 5.83 11.29 17.09 19.19 27.15 37.85 42.01 JAN 0.15 0.33 0.27 0.15 0.22 0.18
FEB 0.15 0.18 0.22 1.51 4.99 14.29 38.25 43.12 FEB 0.15 0.18 0.18 0.17 0.17 0.31
MAR 0.16 1.23 0.92 7.08 11.06 24.24 33.72 48.16 MAR 0.12 0.13 0.14 0.13 0.14 0.95
APR 0.14 0.24 3.71 10.60 15.86 23.62 32.03 36.94 APR 0.12 0.11 0.14 0.12 0.13 0.13
MAY 0.17 0.17 0.18 0.41 3.52 9.78 21.57 30.13 MAY 0.10 0.10 0.10 0.09 0.09 0.10
JUN 0.11 0.09 0.14 0.49 2.00 5.81 15.60 26.78 JUN 0.10 0.12 0.15 0.09 0.11 0.07
JUL 0.64 1.41 4.76 10.57 13.96 23.46 35.53 40.94 JUL 0.14 0.13 0.22 0.18 0.16 0.12
AUG 0.09 0.09 0.10 0.10 0.16 2.51 12.02 14.22 AUG 0.07 0.09 0.08 0.09 0.01 0.07
SEP SEP 0.13 0.24 0.16 0.12 0.17 2.75
OCT 0.09 0.09 0.09 2.02 2.26 5.61 13.95 18.19 OCT 0.08 0.08 0.08 0.07 0.07 0.07
NOV 0.10 1.20 0.43 3.90 8.64 18.19 27.07 45.52 NOV 0.10 0.11 0.12 0.11 0.11 1.02
DEC 0.09 0.21 0.12 2.10 5.86 15.04 19.95 41.44 DEC 0.06 0.07 0.07 0.07 0.07 0.08
mean 0.22 0.98 2.00 5.08 7.95 15.43 26.14 35.22 mean 0.11 0.14 0.14 0.11 0.12 0.49
std dev 0.22 1.69 3.48 5.56 6.30 8.62 9.92 11.34 std dev 0.03 0.08 0.06 0.04 0.06 0.79
median 0.14 0.21 0.22 2.10 5.86 15.04 27.07 40.94 median 0.11 0.12 0.14 0.11 0.12 0.12
max 0.67 5.83 11.29 17.09 19.19 27.15 38.25 48.16 max 0.15 0.33 0.27 0.18 0.22 2.75
min 0.09 0.09 0.09 0.10 0.16 2.51 12.02 14.22 min 0.06 0.07 0.07 0.07 0.01 0.07
ANC SAR GS NC403 PB LRC ROC NCF117 SC-CH B210 COL SRWC 6RC LCO GCO SR BRN HAM
JAN 0.09 0.16 0.15 0.56 0.46 0.12 0.15 0.09 1.61 JAN 0.10 0.06 0.08 0.16 0.10 0.13 0.09 0.16 0.14
FEB 0.08 0.16 0.20 0.40 0.85 0.12 0.14 0.11 0.26 FEB 0.10 0.06 0.08 0.15 0.11 0.13 0.10 0.16 0.18
MAR 0.08 0.18 0.16 0.57 0.50 0.12 0.14 0.14 2.62 MAR 0.10 0.06 0.07 0.14 0.09 0.13 0.08 0.14 0.16
APR 0.11 0.13 0.13 0.34 0.51 0.11 0.12 0.13 1.84 APR 0.09 0.06 0.07 0.11 0.08 0.15 0.08 0.11 0.10
MAY 0.09 0.15 0.13 0.38 1.75 0.11 0.11 0.08 0.12 MAY 0.09 0.06 0.08 0.15 0.10 0.17 0.09 0.14 0.17
JUN 0.07 0.18 0.16 0.30 1.24 0.09 0.11 0.08 0.07 JUN 0.08 0.06 0.07 0.13 0.10 0.13 0.08 0.12 0.13
JUL 0.07 0.30 0.28 1.59 4.56 0.16 0.18 0.13 4.52 JUL 0.09 0.06 0.09 0.16 0.12 0.36 0.11 0.13 0.16
AUG 0.07 0.15 0.14 0.63 2.43 0.15 0.19 0.11 0.26 AUG 0.08 0.06 0.06 0.09 0.08 0.10 0.06 0.14 0.11
SEP SEP
OCT 0.06 0.16 0.15 0.45 0.87 0.13 0.12 0.09 0.17 OCT 0.09 0.06 0.07 0.13 0.10 0.15 0.08 0.12 0.18
NOV 0.07 0.16 0.14 0.39 0.47 0.12 0.14 0.10 0.15 NOV 0.10 0.05 0.07 0.14 0.10 0.15 0.07 0.12 0.17
DEC 0.08 0.14 0.13 0.33 0.44 0.12 0.13 0.11 0.11 DEC 0.07 0.05 0.06 0.11 0.08 0.10 0.06 0.10 0.14
mean 0.08 0.17 0.16 0.54 1.28 0.12 0.14 0.11 1.06 mean 0.09 0.06 0.07 0.13 0.10 0.16 0.08 0.13 0.15
std dev 0.01 0.05 0.04 0.36 1.26 0.02 0.03 0.02 1.45 std dev 0.01 0.00 0.01 0.02 0.01 0.07 0.02 0.02 0.03
median 0.08 0.16 0.15 0.40 0.85 0.12 0.14 0.11 0.26 median 0.09 0.06 0.07 0.14 0.10 0.13 0.08 0.13 0.16
max 0.11 0.30 0.28 1.59 4.56 0.16 0.19 0.14 4.52 max 0.10 0.06 0.09 0.16 0.12 0.36 0.11 0.16 0.18
min 0.06 0.13 0.13 0.30 0.44 0.09 0.11 0.08 0.07 min 0.07 0.05 0.06 0.09 0.08 0.10 0.06 0.10 0.10
27
Table 2.4 pH during 2018 at the Lower Cape Fear River Program stations.
NAV HB BRR M61 M54 M35 M23 M18 NC11 AC DP BBT IC NCF6
JAN 7.5 7.4 7.5 7.6 7.8 8.0 8.1 8.1 JAN 6.4 6.9 6.9 6.4 6.8 6.7
FEB 6.4 6.5 7.0 6.8 7.3 7.7 8.1 8.1 FEB 6.2 6.6 6.7 6.7 6.7 6.4
MAR 7.0 7.1 7.1 7.1 7.5 7.9 8.0 7.7 MAR 6.8 6.9 6.9 6.8 6.9 6.8
APR 6.9 6.9 6.9 7.1 7.3 7.7 8.0 8.0 APR 6.9 6.9 6.8 6.7 6.8 6.8
MAY 6.7 6.7 6.7 6.6 6.7 7.0 7.5 7.7 MAY 6.7 6.7 6.7 6.4 6.5 6.3
JUN 6.4 6.1 6.5 6.2 6.6 6.7 7.1 7.6 JUN 6.5 6.6 6.7 6 6.4 5.8
JUL 6.5 6.8 6.8 7.0 7.1 7.5 7.9 8.0 JUL 6.7 6.7 6.9 6.6 6.6 5.9
AUG 6.2 6.3 6.3 6.0 6.3 6.5 6.9 7.0 AUG 6.2 6.2 6.2 6.1 6.2 5.7
SEP SEP 6.7 7.0 6.7 6.4 6.6 6.4
OCT 6.4 6.5 6.7 6.6 6.8 7.0 7.1 7.4 OCT 6.4 6.2 6.1 5.8 5.9 5.5
NOV 6.9 7.3 7.2 7.5 7.4 7.8 8.0 8.0 NOV 6.5 6.5 6.7 6.7 6.7 6.6
DEC 7.1 7.1 7.6 7.0 7.6 7.8 7.9 8.0 DEC 6.1 5.8 5.7 5.5 5.6 5.7
mean 6.7 6.8 6.9 6.9 7.1 7.4 7.7 7.8 mean 6.5 6.6 6.6 6.3 6.5 6.2
std dev 0.4 0.4 0.4 0.5 0.5 0.5 0.5 0.3 std dev 0.3 0.4 0.4 0.4 0.4 0.5
median 6.7 6.8 6.9 7.0 7.3 7.7 7.9 8.0 median 6.5 6.7 6.7 6.4 6.6 6.4
max 7.5 7.4 7.6 7.6 7.8 8.0 8.1 8.1 max 6.9 7.0 6.9 6.8 6.9 6.8
min 6.2 6.1 6.3 6.0 6.3 6.5 6.9 7.0 min 6.1 5.8 5.7 5.5 5.6 5.5
ANC SAR GS NC403 PB LRC ROC NCF117 SC-CH B210 COL SRWC 6RC LCO GCO SR BRN HAM
JAN 4.9 6.4 6.7 6.6 6.6 6.5 6.1 5.9 6.3 JAN 5.5 3.6 5.6 6.3 5.9 6.0 5.8 6.4 6.4
FEB 5.2 6.5 6.4 6.7 6.6 6.7 6.5 5.6 6.2 FEB 5.4 3.9 5.3 6.3 6.3 6.3 6.0 6.6 6.8
MAR 5.3 6.4 6.9 6.5 6.7 6.9 6.5 6.6 6.5 MAR 6.8 4.0 6.1 6.9 6.7 6.7 6.5 5.8 6.2
APR 6.1 6.7 7.0 6.6 6.8 7.0 6.8 6.9 7.2 APR 6.3 4.1 5.9 6.6 6.2 6.6 6.3 6.7 6.5
MAY 6.1 6.7 6.8 6.8 6.6 7.1 6.7 6.1 6.4 MAY 6.3 4.0 6.3 7.1 6.9 6.9 6.3 7.1 7.1
JUN 4.8 6.7 6.7 6.4 6.6 6.8 6.6 6.0 6.1 JUN 6.1 4.0 5.9 6.8 6.7 6.6 6.2 6.9 6.8
JUL 6 6.8 7.0 7.0 7.0 7.7 7.0 6.5 6.4 JUL 6.1 4.0 6.3 7.0 6.9 7.0 6.7 6.7 7.0
AUG 5.7 6.4 6.5 6.6 6.7 7.1 6.9 6.2 6.9 AUG 6.0 3.9 5.7 6.3 5.7 6.2 5.9 6.9 6.6
SEP SEP
OCT 4.3 6.4 6.7 6.6 6.6 6.9 6.4 6.0 6.3 OCT 6.0 4.1 5.9 6.6 6.5 6.4 6.2 6.3 6.6
NOV 4.8 6.4 6.8 6.6 6.6 6.3 6.4 5.6 6.3 NOV 6.0 4.1 5.9 6.6 6.5 6.6 6.3 6.7 6.9
DEC 5.0 6.5 6.8 6.6 6.7 6.7 6.5 5.9 6.3 DEC 5.4 3.5 5.1 5.8 5.7 6.6 6.5 6.3 7.0
mean 5.3 6.5 6.8 6.6 6.7 6.9 6.6 6.1 6.4 mean 6.0 3.9 5.8 6.6 6.4 6.5 6.2 6.6 6.7
std dev 0.6 0.2 0.2 0.2 0.1 0.4 0.3 0.4 0.3 std dev 0.4 0.2 0.4 0.4 0.4 0.3 0.3 0.4 0.3
median 5.2 6.5 6.8 6.6 6.6 6.9 6.5 6.0 6.3 median 6.0 4.0 5.9 6.6 6.5 6.6 6.3 6.7 6.8
max 6.1 6.8 7.0 7.0 7.0 7.7 7.0 6.9 7.2 max 6.8 4.1 6.3 7.1 6.9 7.0 6.7 7.1 7.1
min 4.3 6.4 6.4 6.4 6.6 6.3 6.1 5.6 6.1 min 5.4 3.5 5.1 5.8 5.7 6.0 5.8 5.8 6.2
28
Table 2.5 Dissolved Oxygen (mg/l) during 2018 at the Lower Cape Fear River Program stations.
NAV HB BRR M61 M54 M35 M23 M18 NC11 AC DP BBT IC NCF6
JAN 12.7 12.3 12.1 12.1 12.2 12.2 12.0 11.8 JAN 12.9 12.6 12.5 13.6 12.9 12.3
FEB 10.5 9.9 10.3 9.1 10.2 10.4 10.3 10.2 FEB 11.5 11.4 11.5 11.3 11.5 10.0
MAR 9.1 9.0 9.1 8.8 9.1 8.9 9.2 8.3 MAR 10.2 10.1 10.0 9.8 9.7 8.6
APR 7.5 7.4 7.3 7.3 7.3 7.6 8.2 8.3 APR 9.2 8.9 8.3 7.9 8.4 6.6
MAY 5.1 4.9 4.9 4.6 4.8 5.6 6.5 6.4 MAY 7.5 7.2 7.1 5.7 6.2 5.0
JUN 4.4 3.5 5.0 3.7 4.7 4.5 5.2 5.5 JUN 5.9 5.5 5.2 3.7 4.4 2.8
JUL 3.8 4.3 5.2 4.5 4.5 5.5 6.1 6.1 JUL 6.1 5.8 5.9 5.4 5.3 4.2
AUG 4.8 5.1 5.1 4.1 4.0 4.0 4.6 4.7 AUG 6.2 6.0 5.8 4.8 5.1 3.4
SEP SEP 5.4 4.9 4.2 3.5 3.6 3.6
OCT 4.8 4.4 4.2 3.8 4.3 4.5 5.2 5.9 OCT 4.9 4.5 2.6 0.2 0.2 0.2
NOV 7.5 7.5 7.6 7.2 7.8 8.2 8.2 7.4 NOV 8.8 8.8 8.6 8.3 8.0 6.8
DEC 9.4 9.4 9.5 9.5 9.7 9.6 9.7 8.6 DEC 10.1 9.9 9.6 8.8 9.1 8.3
mean 7.2 7.1 7.3 6.8 7.1 7.4 7.7 7.6 mean 8.2 8.0 7.6 6.9 7.0 6.0
std dev 2.9 2.8 2.6 2.8 2.9 2.7 2.4 2.1 std dev 2.6 2.7 3.0 3.7 3.6 3.4
median 7.5 7.4 7.3 7.2 7.3 7.6 8.2 7.4 median 8.2 8.0 7.7 6.8 7.1 5.8
max 12.7 12.3 12.1 12.1 12.2 12.2 12.0 11.8 max 12.9 12.6 12.5 13.6 12.9 12.3
min 3.8 3.5 4.2 3.7 4.0 4.0 4.6 4.7 min 4.9 4.5 2.6 0.2 0.2 0.2
ANC SAR GS NC403 PB LRC ROC NCF117 SC-CH B210 COL SRWC 6RC LCO GCO SR BRN HAM
JAN 10.0 12.8 13.8 11.7 12.2 13.6 12.3 9.0 10.6 JAN 10.8 9.8 10.5 10.3 10.4 10.8 10.9 12.1 11.5
FEB 9.0 10.1 10.7 9.9 9.5 11.4 9.7 9.8 9.3 FEB 8.7 7.1 8.4 8.9 8.6 7.7 8.6 10.3 10.2
MAR 11.0 10.8 11.9 11.7 11.4 12.2 11.1 8.4 9.8 MAR 9.6 9.1 9.9 10.0 10.1 9.4 10.4 9.1 9.5
APR 8.6 8.4 10.1 8.5 8.8 10.1 8.7 6.6 7.5 APR 6.5 6.3 7.6 7.6 7.4 6.3 5.1 8.0 7.7
MAY 7.0 6.5 7.7 6.4 3.9 8.8 7.5 4.9 5.2 MAY 5.7 6.3 6.9 7.8 7.7 6.9 2.3 7.9 6.4
JUN 4.9 5.9 5.4 4.6 4.4 7.4 6.4 3.0 3.5 JUN 4.7 5.1 5.9 6.6 6.8 5.7 4.6 7.2 6.5
JUL 3.4 7.1 1.7 3.1 6.6 8.8 4.6 3.2 3.5 JUL 4.4 5.2 4.7 6.4 5.6 5.6 5.4 7.2 5.9
AUG 4.1 4.9 2.0 2.6 4.7 6.7 5.1 3.3 4.0 AUG 4.1 4.6 5.6 5.0 5.4 4.8 3.7 6.9 6.1
SEP SEP
OCT 1.7 3.7 3.5 6.5 5.9 7.1 4.5 0.2 0.3 OCT 3.2 3.6 5.5 6.8 6.5 6.1 4.6 9.2 8.2
NOV 8.9 11.1 12.1 10.8 10.6 11.6 10.5 7.5 8.1 NOV 6.0 5.4 7.5 8.1 8.0 7.3 5.8 7.8 6.7
DEC 8.8 9.8 10.9 9.9 10.2 10.9 9.2 8.0 8.4 DEC 9.0 7.4 8.9 8.5 9.0 11.7 9.8 11.0 11.0
mean 7.0 8.3 8.2 7.8 8.0 9.9 8.1 5.8 6.4 mean 6.6 6.4 7.4 7.8 7.8 7.5 6.5 8.8 8.2
std dev 3.0 2.9 4.3 3.3 3.0 2.3 2.7 3.1 3.3 std dev 2.5 1.9 1.9 1.6 1.7 2.2 2.9 1.7 2.1
median 8.6 8.4 10.1 8.5 8.8 10.1 8.7 6.6 7.5 median 6.0 6.3 7.5 7.8 7.7 6.9 5.4 8.0 7.7
max 11.0 12.8 13.8 11.7 12.2 13.6 12.3 9.8 10.6 max 10.8 9.8 10.5 10.3 10.4 11.7 10.9 12.1 11.5
min 1.7 3.7 1.7 2.6 3.9 6.7 4.5 0.2 0.3 min 3.2 3.6 4.7 5.0 5.4 4.8 2.3 6.9 5.9
29
0
1
2
3
4
5
6
7
8
9
NC11 AC DP IC NAV HB BRR M61 M54 M35 M23 M18 NCF117 NCF6 B210 BBT
Di
s
s
o
l
v
e
d
O
x
y
g
e
n
(
m
g
/
L
)
Figure 2.2 Dissolved Oxygen at the Lower Cape Fear River Program mainstem stations
1995-2017 versus 2018.
1995-2017
2018
30
Table 2.6 Field Turbidity (NTU) during 2018 at the Lower Cape Fear River Program stations.
NAV HB BRR M61 M54 M35 M23 M18 NC11 AC DP BBT IC NCF6
JAN 12 7 5 5 4 5 3 3 JAN 5 7 8 5 8 12
FEB 21 24 21 21 21 10 13 17 FEB 87 85 40 30 22 10
MAR MAR 20 18 18 10 14 6
APR 11 13 11 6 5 4 3 6 APR 17 13 11 9 10 6
MAY 9 7 7 7 9 8 5 5 MAY 28 28 29 9 13 5
JUN 7 4 7 5 7 6 3 3 JUN 13 12 13 5 7 3
JUL 8 5 6 3 3 3 2 2 JUL 15 19 11 9 7 6
AUG 22 14 13 8 14 8 4 4 AUG 30 26 24 13 15 5
SEP SEP 17 16 14 8 14 22
OCT 15 13 13 10 11 9 4 4 OCT 22 21 13 5 9 6
NOV 17 14 17 12 10 4 4 10 NOV 23 19 14 11 7 7
DEC 7 6 7 4 12 3 2 9 DEC 30 30 28 9 17 4
mean 13 11 11 8 10 6 4 6 mean 26 25 19 10 12 8
std dev 6 6 5 5 5 3 3 5 std dev 21 20 10 7 5 5
median 12 10 9 7 10 6 4 5 median 21 19 14 9 12 6
max 22 24 21 21 21 10 13 17 max 87 85 40 30 22 22
min 7 4 5 3 3 3 2 2 min 5 7 8 5 7 3
ANC SAR GS NC403 PB LRC ROC NCF117 SC-CH B210 COL SRWC 6RC LCO GCO SR BRN HAM
JAN 10 3 1 2 5 13 7 18 11 JAN 5 6 5 13 10 3 8 8 20
FEB 10 2 2 5 10 10 6 6 14 FEB 3 3 2 7 3 2 3 6 6
MAR 9 4 2 8 12 6 10 6 11 MAR 2 4 1 5 3 2 5 8 7
APR 9 3 2 4 12 6 9 3 7 APR 4 5 8 22 13 4 23 13 22
MAY 13 5 2 4 9 4 6 5 9 MAY 5 7 3 5 4 4 18 6 7
JUN 10 8 3 6 5 7 10 4 8 JUN 4 7 4 7 6 4 11 5 6
JUL 9 2 16 3 25 4 5 4 4 JUL 3 8 7 2 2 3 10 4 6
AUG 7 4 3 3 8 5 8 4 10 AUG 2 15 3 4 5 3 5 4 5
SEP SEP
OCT 3 4 4 3 5 5 5 3 5 OCT 2 2 2 7 3 3 3 6 4
NOV 6 2 1 2 6 4 3 3 7 NOV 1 2 0 3 1 1 1 4 3
DEC 4 0 0 0 4 1 0 0 7 DEC 1 0 0 1 0 0 0 4 3
mean 8 3 3 4 9 6 6 5 8 mean 3 5 3 7 5 3 8 6 8
std dev 3 2 4 2 6 3 3 5 3 std dev 1 4 3 6 4 1 7 3 7
median 9 3 2 3 8 5 6 4 8 median 3 5 3 5 3 3 5 6 6
max 13 8 16 8 25 13 10 18 14 max 5 15 8 22 13 4 23 13 22
min 3 0 0 0 4 1 0 0 4 min 1 0 0 1 0 0 0 4 3
31
0
5
10
15
20
25
30
NC11 AC DP IC NAV HB BRR M61 M54 M35 M23 M18 NCF117 NCF6 B210 BBT
Fi
e
l
d
T
u
r
b
i
d
i
t
y
(
N
T
U
)
Figure 2.3 Field Turbidity at the Lower Cape Fear River Program mainstem stations,
1995-2017 versus 2018.
1995-2017
2018
32
Table 2.7 Total Suspended Solids (mg/L) during 2018 at the Lower Cape Fear River Program stations.
NAV HB BRR M61 M54 M35 M23 M18 NC11 AC DP IC NCF6
JAN 10.8 9.7 8.0 7.6 7.4 9.9 20.3 13.4 JAN 1.4 4.5 5.8 5.8 9.3
FEB 10.6 11.4 11.0 15.8 22.9 11.2 28.9 36.0 FEB 85.0 72.5 38.4 17.2 10.4
MAR 7.3 7.2 12.6 11.6 15.0 15.6 41.4 74.4 MAR 27.3 23.3 23.9 15.1 9.4
APR 10.5 11.6 12.1 9.0 8.5 9.9 11.0 17.4 APR 13.0 8.7 5.6 6.5 7.7
MAY 6.5 5.4 5.0 9.3 12.1 12.4 10.6 12.7 MAY 29.9 30.5 29.9 5.8 4.8
JUN 4.6 4.3 5.4 4.4 9.0 6.6 6.9 7.9 JUN 9.0 8.6 10.7 3.9 3.7
JUL 5.8 4.1 8.9 7.4 6.8 8.0 9.5 9.0 JUL 16.6 16.0 14.3 10.5 10.2
AUG 27.0 9.1 9.9 9.9 13.3 8.7 7.7 9.4 AUG 53.2 36.4 46.2 28.6 6.0
SEP SEP 13.5 8.8 10.9 9.7 41.1
OCT 15.8 8.6 6.9 8.1 8.7 8.8 7.0 8.0 OCT 23.6 27.4 13.3 13.0 14.3
NOV 8.1 8.6 9.6 10.1 11.4 9.1 9.3 24.9 NOV 27.0 21.0 14.8 4.1 7.2
DEC 6.4 5.4 6.2 5.2 17.4 7.1 7.0 39.2 DEC 28.4 28.7 25.0 15.0 1.4
mean 10.3 7.8 8.7 8.9 12.0 9.8 14.5 22.9 mean 27.3 23.9 19.9 11.3 11.3
std dev 6.4 2.7 2.6 3.1 4.9 2.6 11.2 20.3 std dev 22.4 18.4 13.0 7.1 7.1
median 8.1 8.6 8.9 9.0 11.4 9.1 9.5 13.4 median 25.3 22.2 14.6 10.9 10.1
max 27.0 11.6 12.6 15.8 22.9 15.6 41.4 74.4 max 85.0 72.5 46.2 6.8 28.6
min 4.6 4.1 5.0 4.4 6.8 6.6 6.9 7.9 min 1.4 4.5 5.6 10.6 3.9
ANC SAR GS NC403 PB LRC ROC NCF117 SC-CH B210 COL SRWC 6RC LCO GCO SR BRN HAM
JAN 1.4 3.0 6.6 6.6 5.1 7.7 9.3 JAN 1.8 1.4
FEB 3.4 3.5 5.7 9.5 6.2 3.5 10.2 FEB 1.3 1.4
MAR 1.4 5.1 6.7 1.4 5.6 3.1 12.7 MAR 1.4 1.5
APR 3.4 4.3 5.2 3.8 13.0 4.2 11.7 APR 3.5 5.8
MAY 5.9 6.1 5.9 1.4 7.8 5.4 13.0 MAY 4.2 3.7
JUN 9.9 6.3 6.0 7.5 12.9 2.9 15.6 JUN 3.9 5.4
JUL 1.3 5.8 10.8 1.3 19.0 7.0 7.2 JUL 1.3 1.3
AUG 9.0 4.0 7.3 1.5 4.1 5.5 15.8 AUG 4.2 4.1
SEP SEP
OCT 6.2 8.3 6.3 4.0 6.6 16.1 13.3 OCT 1.4 4.3
NOV 1.3 1.3 2.9 1.3 1.3 1.4 5.6 NOV 1.3 1.3
DEC 1.5 1.3 1.4 1.4 1.3 1.3 7.8 DEC 1.3 1.8
mean 4.1 4.5 5.9 3.6 7.5 5.3 11.1 mean 2.3 2.9
std dev 3.2 2.2 2.4 3.0 5.4 4.1 3.4 std dev 1.3 1.8
median 3.4 4.3 6.0 1.5 6.2 4.2 11.7 median 1.4 1.8
max 9.9 8.3 10.8 9.5 19.0 16.1 15.8 max 4.2 5.8
min 1.3 1.3 1.4 1.3 1.3 1.3 5.6 min 1.3 1.3
33
Table 2.8 Light Attenuation (k) during 2018 at the Lower Cape Fear River Program stations.
NAV HB BRR M61 M54 M35 M23 M18 NC11 AC DP BBT IC NCF6
JAN JAN
FEB 3.55 4.54 4.37 3.62 4.01 2.20 2.19 2.44 FEB 7.10 6.42 4.52 3.64 3.05 4.22
MAR MAR 3.23 3.45 3.08 2.95 2.68 4.16
APR 3.75 3.37 3.06 2.49 2.55 1.96 1.41 1.11 APR 2.83 2.67 2.90 2.79 2.91 3.46
MAY 3.01 2.75 3.65 2.25 1.96 MAY 4.02 4.23 3.63 3.74 3.58 3.90
JUN 4.06 4.09 3.20 3.95 3.96 3.54 2.53 2.74 JUN 2.60 2.99 3.31 4.20 3.30 3.86
JUL 3.33 3.12 3.66 3.09 2.52 1.73 1.90 JUL 2.67 2.65 2.87
AUG 4.56 4.02 3.48 2.71 4.62 3.72 3.31 3.24 AUG 4.78 4.75 4.36 3.78 4.47 4.58
SEP SEP 1.00 1.13 1.44 1.02 1.33 1.03
OCT OCT 1.72 1.76 0.74 0.75 1.54 1.31
NOV NOV
DEC DEC
mean 3.98 3.73 3.33 3.29 3.65 2.79 2.24 2.23 mean 3.33 3.34 2.98 2.86 2.86 3.32
std dev 0.44 0.58 0.56 0.64 0.73 0.80 0.66 0.74 std dev 1.80 1.61 1.24 1.30 1.03 1.36
max 4.56 4.54 4.37 3.95 4.62 3.72 3.31 3.24 max 7.10 6.42 4.52 4.20 4.47 4.58
min 3.55 3.01 2.75 2.49 2.55 1.96 1.41 1.11 min 1.00 1.13 0.74 0.75 1.33 1.03
34
Table 2.9 Total Nitrogen (mg/l) during 2018 at the Lower Cape Fear River Program stations.
NAV HB BRR M61 M54 M35 M23 M18 NC11 AC DP IC NCF6
JAN 1,630 1,090 940 950 890 580 370 510 JAN 1,870 1,880 1,750 1,350 1,070
FEB 1,630 1,920 1,620 1,550 1,600 1,020 680 850 FEB 2,330 2,190 1,880 1,730 1,200
MAR 1,360 1,290 1,400 1,240 1,200 1,330 580 920 MAR 1,700 1,590 1,430 1,330 950
APR 1,200 1,190 1,290 1,050 830 730 480 630 APR 1,510 1,480 1,620 1,330 1,110
MAY 760 1,540 1,530 1,120 1,100 900 650 680 MAY 1,370 1,330 1,630 1,890 1,790
JUN 1,050 1,230 1,190 1,080 1,140 1,070 760 780 JUN 1,160 1,040 1,150 970 670
JUL 890 740 440 350 420 210 50 50 JUL 1,470 1,640 1,480 1,480 840
AUG 970 930 1,030 950 970 920 770 650 AUG 1,580 1,080 1,130 980 1,000
SEP SEP 1,860 1,980 1,460 1,530 1,320
OCT 1,960 2,020 1,930 1,760 1,480 1,340 1,140 780 OCT 1,110 910 1,010 1,010 1,700
NOV 1,610 1,390 1,480 1,400 1,330 1,350 1,280 1,260 NOV 1,390 1,640 1,640 1,670 1,470
DEC 820 900 910 810 780 830 580 120 DEC 1,060 880 940 1,070 970
mean 1,262 1,295 1,251 1,115 1,067 935 667 657 mean 1,534 1,470 1,427 1,362 1,174
std dev 401 405 409 380 338 350 337 344 std dev 367 430 304 311 340
median 1,200 1,230 1,290 1,080 1,100 920 650 680 median 1,490 1,535 1,470 1,340 1,090
max 1,960 2,020 1,930 1,760 1,600 1,350 1,280 1,260 max 2,330 2,190 1,880 1,890 1,790
min 760 740 440 350 420 210 50 50 min 1,060 880 940 970 670
ANC SAR GS NC403 PB LRC ROC NCF117 SC-CH B210 COL SR-WC 6RC LCO GCO SR BRN HAM
JAN 3,000 1,900 670 2,520 2,020 2,360 2,070 1,410 950 JAN 950 1,040 1,140 2,150 1,630 1,030 820 1,570 2,030
FEB 1,480 1,120 1,940 3,960 4,100 1,650 2,050 1,220 700 FEB 870 820 480 1,550 1,320 850 550 1,280 1,260
MAR 2,240 1,230 680 2,310 1,680 960 1,170 1,490 1,010 MAR 820 1,000 590 1,370 1,280 820 850 920 840
APR 2,130 1,430 930 2,950 2,270 1,350 1,630 1,440 820 APR 850 800 720 2,040 1,090 1,220 1,130 930 1,350
MAY 720 1,230 930 2,540 1,360 2,200 1,510 1,600 1,880 MAY 970 1,100 950 2,030 960 1,580 1,540 1,080 900
JUN 1,120 1,290 630 1,600 960 1,370 1,280 870 910 JUN 890 1,100 830 1,640 850 1,040 1,170 870 870
JUL 1,630 910 1,300 1,270 800 350 6,480 1,140 800 JUL 1,230 1,940 900 960 960 1,300 1,310 1,060 1,560
AUG 1,690 1,140 1,100 1,280 2,490 1,210 2,890 1,160 1,010 AUG 1,440 2,140 1,590 1,400 1,410 860 1,450 1,280 1,430
SEP SEP
OCT 2,530 1,520 1,640 2,970 2,110 1,170 2,140 2,750 1,840 OCT 1,530 2,020 1,560 2,310 1,350 1,480 1,110 1,750 910
NOV 1,820 1,550 960 4,540 4,820 1,290 1,790 1,090 710 NOV 1,280 1,900 1,250 1,790 1,400 1,360 1,050 1,740 970
DEC 1,130 1,170 950 4,900 5,430 1,260 1,850 1,450 1,070 DEC 1,470 750 950 2,560 1,840 1,420 660 1,630 1,820
mean 1,772 1,317 1,066 2,804 2,549 1,379 2,260 1,420 1,064 mean 1,118 1,328 996 1,800 1,281 1,178 1,058 1,283 1,267
std dev 670 269 413 1,237 1,555 551 1,476 490 412 std dev 276 548 361 470 300 272 314 339 412
median 1,690 1,230 950 2,540 2,110 1,290 1,850 1,410 950 median 970 1,100 950 1,790 1,320 1,220 1,110 1,280 1,260
max 3,000 1,900 1,940 4,900 5,430 2,360 6,480 2,750 1,880 max 1,530 2,140 1,590 2,560 1,840 1,580 1,540 1,750 2,030
min 720 910 630 1,270 800 350 1,170 870 700 min 820 750 480 960 850 820 550 870 840
35
Table 2.10 Nitrate/Nitrite (mg/l) during 2018 at the Lower Cape Fear River stations.
NAV HB BRR M61 M54 M35 M23 M18 NC11 AC DP IC NCF6
JAN 630 490 440 350 390 280 170 110 JAN 1,170 980 850 650 270
FEB 630 620 620 550 500 420 180 50 FEB 930 1,090 980 930 400
MAR 660 590 600 540 500 330 80 20 MAR 700 690 730 630 250
APR 500 490 490 350 330 230 180 130 APR 710 680 520 530 210
MAY 760 640 630 320 400 300 250 180 MAY 570 530 530 490 390
JUN 450 330 490 380 440 370 260 180 JUN 660 640 650 470 270
JUL 690 640 440 350 320 210 90 50 JUL 870 1,040 880 860 140
AUG 370 430 430 250 270 220 170 150 AUG 480 480 430 380 200
SEP SEP 1,060 880 760 530 220
OCT 760 720 630 560 580 440 240 180 OCT 410 410 310 110 10
NOV 610 490 580 500 430 350 280 60 NOV 690 740 740 670 470
DEC 420 400 410 410 380 330 380 120 DEC 560 580 540 570 570
mean 589 531 524 415 413 316 207 112 mean 734 728 660 568 283
std dev 135 120 89 106 90 77 87 59 std dev 231 224 199 213 152
median 630 490 490 380 400 330 180 120 median 695 685 690 550 260
max 760 720 630 560 580 440 380 180 max 1,170 1,090 980 930 570
min 370 330 410 250 270 210 80 20 min 410 410 310 110 10
ANC SAR GS NC403 PB LRC ROC NCF117 SC-CH B210 COL SR-WC 6RC LCO GCO SR BRN HAM
JAN 1,200 900 170 1,820 1,320 1,260 1,170 510 250 JAN 250 40 440 1,050 730 330 120 770 930
FEB 280 520 1,040 3,160 3,200 1,050 1,050 520 300 FEB 370 20 80 850 720 250 50 680 560
MAR 240 530 80 1,510 880 260 370 290 210 MAR 220 10 90 670 480 220 50 320 240
APR 630 330 30 1,650 970 250 430 240 120 APR 250 10 220 1,140 490 520 230 230 550
MAY 120 330 30 1,340 160 500 610 300 380 MAY 270 10 250 1,130 360 680 340 480 200
JUN 220 690 30 1,000 360 670 580 270 210 JUN 290 10 230 1,040 350 340 370 370 370
JUL 130 210 10 270 10 350 2,280 240 200 JUL 230 40 400 460 260 500 110 460 160
AUG 90 140 10 380 990 410 1,690 160 110 AUG 140 40 90 300 210 60 50 480 230
SEP SEP
OCT 30 220 40 1,670 1,010 170 540 50 40 OCT 330 20 460 1,210 450 480 110 950 310
NOV 220 850 360 3,740 3,920 690 1,090 290 210 NOV 380 10 250 590 400 360 50 840 170
DEC 230 570 350 3,900 4,430 560 950 450 370 DEC 870 50 350 1,860 1,340 920 160 830 1,120
mean 308 481 195 1,858 1,568 561 978 302 218 mean 327 24 260 936 526 424 149 583 440
std dev 334 259 309 1,238 1,543 342 584 143 105 std dev 193 16 139 431 316 235 116 241 323
median 220 520 40 1,650 990 500 950 290 210 median 270 20 250 1,040 450 360 110 480 310
max 1,200 900 1,040 3,900 4,430 1,260 2,280 520 380 max 870 50 460 1,860 1,340 920 370 950 1,120
min 30 140 10 270 10 170 370 50 40 min 140 10 80 300 210 60 50 230 160
36
0
100
200
300
400
500
600
700
800
NC11 AC DP IC NAV HB BRR M61 M54 M35 M23 M18 NCF117 NCF6 B210
Ni
t
r
a
t
e
+
N
i
t
r
i
t
e
(
mg/
L
)
Figure 2.4 Nitrate + Nitrite at the Lower Cape Fear River Program mainstem stations,
1995-2017 versus 2018.
1995-2017
2018
37
Table 2.11 Ammonia (mg/l) during 2018 at the Lower Cape Fear River stations.
NAV HB BRR M61 M54 M35 M23 M18 NC11 AC DP IC NCF6
JAN 100 150 170 170 200 160 80 50 JAN 80 160 150 110 80
FEB 110 100 130 110 200 110 10 10 FEB 50 70 50 50 50
MAR 30 60 60 70 100 40 10 10 MAR 90 110 100 110 80
APR 90 100 90 90 90 80 60 10 APR 110 110 110 100 30
MAY 130 150 130 90 110 130 110 90 MAY 90 110 100 70 80
JUN 80 80 70 90 210 120 100 80 JUN 110 120 190 130 100
JUL 60 70 10 60 70 30 10 10 JUL 150 160 160 110 100
AUG 110 80 150 170 200 140 150 90 AUG 140 110 80 100 120
SEP SEP 80 280 140 100 50
OCT 140 140 160 230 200 210 190 200 OCT 50 40 70 50 170
NOV 90 90 130 110 120 60 10 170 NOV 90 80 90 90 100
DEC 80 60 150 90 120 60 10 120 DEC 90 50 60 20 30
mean 93 98 114 116 147 104 67 76 mean 94 117 108 87 83
std dev 31 34 50 52 54 55 64 67 std dev 30 64 43 32 40
median 90 90 130 90 120 110 60 80 median 90 110 100 100 80
max 140 150 170 230 210 210 190 200 max 150 280 190 130 170
min 30 60 10 60 70 30 10 10 min 50 40 50 20 30
ANC SAR GS NC403 PB LRC ROC NCF117 SC-CH B210 COL SR-WC 6RC LCO GCO SR BRN HAM
JAN 70 60 40 90 160 90 270 80 110 JAN 30 20 20 70 10 10 10 40 40
FEB 180 20 10 70 130 80 320 40 130 FEB 10 40 10 60 20 20 10 70 280
MAR 40 30 10 70 60 70 120 50 50 MAR 40 70 50 60 50 40 40 90 120
APR 200 30 20 140 210 100 120 80 60 APR 20 40 10 170 50 60 240 40 120
MAY 130 80 40 130 1,240 300 190 120 160 MAY 180 400 70 100 80 100 620 100 260
JUN 240 60 40 110 290 390 70 170 110 JUN 60 280 40 60 40 100 90 50 60
JUL 230 70 50 200 70 60 10 80 130 JUL 80 340 70 30 50 70 320 70 50
AUG 170 80 50 100 80 60 110 580 100 AUG 130 170 90 90 90 80 90 130 120
SEP SEP
OCT 540 260 310 170 180 200 380 320 380 OCT 170 570 150 110 110 90 100 140 70
NOV 330 10 10 120 50 50 30 30 30 NOV 80 240 70 70 70 60 50 100 40
DEC 450 100 30 130 140 240 240 100 130 DEC 30 90 30 130 10 10 10 100 80
mean 235 73 55 121 237 149 169 150 126 mean 75 205 55 86 53 58 144 85 113
std dev 153 68 86 40 340 116 121 164 93 std dev 60 178 41 39 33 34 187 34 84
median 200 60 40 120 140 90 120 80 110 median 60 170 50 70 50 60 90 90 80
max 540 260 310 200 1,240 390 380 580 380 max 180 570 150 170 110 100 620 140 280
min 40 10 10 70 50 50 10 30 30 min 10 20 10 30 10 10 10 40 40
38
0
5000
10000
15000
20000
25000
0
100
200
300
400
500
600
700
800
900
1000
20
1
0
20
1
1
20
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8
Fe
c
a
l
C
o
l
i
f
o
r
m
B
a
c
t
e
r
i
a
(
C
F
U
/
1
0
0
m
L
)
Am
m
o
n
i
a
(
m
g
/
L
)
Figure 2.5 Ammonia and Fecal Coliform Bacteria at COL 2010-2018.
Ammonia
Fecal
39
Table 2.12 Total Kjeldahl Nitrogen (mg/l) during 2018 at the Lower Cape Fear River Program stations.
NAV HB BRR M61 M54 M35 M23 M18 NC11 AC DP IC NCF6
JAN 1,000 600 500 600 500 300 200 400 JAN 700 900 900 700 800
FEB 1,000 1,300 1,000 1,000 1,100 600 500 800 FEB 1,400 1,100 900 800 800
MAR 700 700 800 700 700 1,000 500 900 MAR 1,000 900 700 700 700
APR 700 700 800 700 500 500 300 500 APR 800 800 1,100 800 900
MAY 50 900 900 800 700 600 400 500 MAY 800 800 1,100 1,400 1,400
JUN 600 900 700 700 700 700 500 600 JUN 500 400 500 500 400
JUL 200 100 50 50 100 50 50 50 JUL 600 600 600 600 700
AUG 600 500 600 700 700 700 600 500 AUG 1,100 600 700 600 800
SEP SEP 800 1,100 700 1,000 1,100
OCT 1,200 1,300 1,300 1,200 900 900 900 600 OCT 700 500 700 900 1,700
NOV 1,000 900 900 900 900 1,000 1,000 1,200 NOV 700 900 900 1,000 1,000
DEC 400 500 500 400 400 500 200 50 DEC 500 300 400 500 400
mean 677 764 732 705 655 623 468 555 mean 800 742 767 792 892
std dev 360 353 324 302 273 289 290 338 std dev 259 261 219 257 375
median 700 700 800 700 700 600 500 500 median 750 800 700 750 800
max 1,200 1,300 1,300 1,200 1,100 1,000 1,000 1,200 max 1,400 1,100 1,100 1,400 1,700
min 50 100 50 50 100 50 50 50 min 500 300 400 500 400
ANC SAR GS NC403 PB LRC ROC NCF117 SC-CH B210 COL SR-WC 6RC LCO GCO SR BRN HAM
JAN 1,800 1,000 500 700 700 1,100 900 900 700 JAN 700 1,000 700 1,100 900 700 700 800 1,100
FEB 1,200 600 900 800 900 600 1,000 700 400 FEB 500 800 400 700 600 600 500 600 700
MAR 2,000 700 600 800 800 700 800 1,200 800 MAR 600 1,000 500 700 800 600 800 600 600
APR 1,500 1,100 900 1,300 1,300 1,100 1,200 1,200 700 APR 600 800 500 900 600 700 900 700 800
MAY 600 900 900 1,200 1,200 1,700 900 1,300 1,500 MAY 700 1,100 700 900 600 900 1,200 600 700
JUN 900 600 600 600 600 700 700 600 700 JUN 600 1,100 600 600 500 700 800 500 500
JUL 1,500 700 1,300 1,000 800 50 4,200 900 600 JUL 1,000 1,900 500 500 700 800 1,200 600 1,400
AUG 1,600 1,000 1,100 900 1,500 800 1,200 1,000 900 AUG 1,300 2,100 1,500 1,100 1,200 800 1,400 800 1,200
SEP SEP
OCT 2,500 1,300 1,600 1,300 1,100 1,000 1,600 2,700 1,800 OCT 1,200 2,000 1,100 1,100 900 1,000 1,000 800 600
NOV 1,600 700 600 800 900 600 700 800 500 NOV 900 1,900 1,000 1,200 1,000 1,000 1,000 900 800
DEC 900 600 600 1,000 1,000 700 900 1,000 700 DEC 600 700 600 700 500 500 500 800 700
mean 1,464 836 873 945 982 823 1,282 1,118 845 mean 791 1,309 736 864 755 755 909 700 827
std dev 545 238 347 238 271 412 1,003 567 425 std dev 270 545 332 238 225 163 288 126 283
median 1,500 700 900 900 900 700 900 1,000 700 median 700 1,100 600 900 700 700 900 700 700
max 2,500 1,300 1,600 1,300 1,500 1,700 4,200 2,700 1,800 max 1,300 2,100 1,500 1,200 1,200 1,000 1,400 900 1,400
min 600 600 500 600 600 50 700 600 400 min 500 700 400 500 500 500 500 500 500
40
Table 2.13 Total Phosphorus (mg/l) during 2018 at the Lower Cape Fear River Program stations.
NAV HB BRR M61 M54 M35 M23 M18 NC11 AC DP IC NCF6
JAN 140 120 90 80 60 50 30 40 JAN 130 70 210 190 230
FEB 60 90 80 100 90 60 40 40 FEB 210 210 160 160 70
MAR 280 260 180 320 170 270 190 180 MAR 230 220 220 190 140
APR 100 120 130 50 40 40 40 80 APR 100 120 80 120 70
MAY 130 100 90 90 80 70 30 30 MAY 140 180 170 200 210
JUN 100 140 270 270 160 120 110 80 JUN 140 130 160 150 130
JUL 210 150 130 130 110 270 90 90 JUL 230 220 270 170 150
AUG 210 160 230 250 330 180 180 210 AUG 170 170 220 130 130
SEP SEP 210 260 160 170 250
OCT 190 230 200 250 160 90 90 70 OCT 150 150 200 220 390
NOV 130 120 140 180 80 80 100 80 NOV 80 110 90 80 100
DEC 100 80 90 70 80 60 70 110 DEC 140 110 90 80 80
mean 150 143 148 163 124 117 88 92 mean 161 163 169 155 155
std dev 62 54 61 91 77 81 53 54 std dev 48 55 57 43 90
median 130 120 130 130 90 80 90 80 median 145 160 165 165 135
max 280 260 270 320 330 270 190 210 max 230 260 270 220 220
min 60 80 80 50 40 40 30 30 min 80 70 80 80 80
ANC SAR GS NC403 PB LRC ROC NCF117 SC-CH B210 COL SR-WC 6RC LCO GCO SR BRN HAM
JAN 390 70 40 70 140 90 100 160 70 JAN 50 70 10 140 50 100 40 50 70
FEB 200 60 40 80 90 60 40 60 70 FEB 30 40 10 90 30 110 30 30 80
MAR 90 60 40 120 100 80 50 70 50 MAR 50 70 10 50 10 150 10 40 80
APR 280 170 60 150 190 160 150 60 30 APR 110 70 60 240 120 370 100 130 170
MAY 120 170 170 210 230 130 210 140 140 MAY 120 110 60 210 90 530 80 110 260
JUN 400 180 160 250 240 150 220 240 190 JUN 150 140 40 160 90 390 90 100 140
JUL 270 300 310 220 240 10 1,390 120 70 JUL 170 240 80 170 160 600 120 80 360
AUG 240 200 220 190 380 110 460 200 120 AUG 180 160 80 180 90 290 100 100 160
SEP SEP
OCT 380 350 380 250 370 170 430 430 360 OCT 160 230 80 180 90 280 90 100 180
NOV 140 40 60 110 160 60 160 70 80 NOV 80 180 10 110 10 210 10 60 110
DEC 120 390 140 170 220 110 150 100 210 DEC 80 140 60 90 50 20 20 70 20
mean 239 181 147 165 215 103 305 150 126 mean 107 132 45 147 72 277 63 79 148
std dev 110 116 111 62 91 47 367 105 92 std dev 50 64 29 55 44 175 39 30 92
median 240 170 140 170 220 110 160 120 80 median 110 140 60 160 90 280 80 80 140
max 400 390 380 250 380 170 1,390 430 360 max 180 240 80 240 160 600 120 130 360
min 90 40 40 70 90 10 40 60 30 min 30 40 10 50 10 20 10 30 20
41
0
20
40
60
80
100
120
140
160
180
NC11 AC DP IC NAV HB BRR M61 M54 M35 M23 M18 NCF117 NCF6 B210
To
t
a
l
P
h
o
s
p
h
o
r
u
s
(
mg/
L
)
Figure 2.5 Total Phosphorus at the Lower Cape Fear River Program mainstem stations,
1995-2017 versus 2018.
1995-2017
2018
42
Table 2.14 Orthophosphate (mg/l) during 2018 at the Lower Cape Fear River Program stations.
NAV HB BRR M61 M54 M35 M23 M18 NC11 AC DP BBT IC NCF6
JAN 50 30 30 30 30 20 10 10 JAN 110 100 80 20 50 10
FEB 30 60 40 60 50 40 30 20 FEB 50 40 50 40 40 80
MAR 20 30 20 40 30 20 10 10 MAR 30 40 50 50 60 20
APR 40 40 30 30 20 20 10 10 APR 40 30 30 20 40 20
MAY 40 30 40 20 40 20 20 10 MAY 30 30 30 30 30 50
JUN 30 60 40 60 50 40 30 20 JUN 50 40 50 40 40 80
JUL 60 60 40 40 40 30 20 10 JUL 70 90 100 80 80 30
AUG 30 30 40 50 50 30 30 30 AUG 30 40 40 50 40 50
SEP SEP 70 110 60 50 50 50
OCT 70 70 70 70 60 50 40 30 OCT 30 30 20 70 40 90
NOV 30 30 30 20 20 20 20 10 NOV 20 30 30 30 30 30
DEC 20 30 20 30 30 20 20 10 DEC 30 40 30 20 20 30
mean 38 43 36 41 38 28 22 15 mean 47 52 48 42 43 45
std dev 16 16 14 17 13 11 10 8 std dev 26 30 23 19 16 26
median 30 30 40 40 40 20 20 10 median 35 40 45 40 40 40
max 70 70 70 70 60 50 40 30 max 110 110 100 80 80 90
min 20 30 20 20 20 20 10 10 min 20 30 20 20 20 10
ANC SAR GS NC403 PB LRC ROC NCF117 SC-CH B210 COL SR-WC 6RC LCO GCO SR BRN HAM
JAN 240 10 5 10 20 10 20 70 10 JAN 20 30 5 50 10 50 5 10 10
FEB 240 40 20 20 70 50 40 60 60 FEB 50 70 10 40 20 150 5 30 40
MAR 120 10 10 20 20 10 10 20 5 MAR 10 20 20 20 5 50 5 10 20
APR 220 10 10 30 30 10 40 20 10 APR 30 50 5 30 20 170 5 10 30
MAY 130 30 30 30 20 10 40 40 50 MAY 40 70 10 40 20 230 10 20 40
JUN 240 40 20 20 70 50 40 60 60 JUN 50 70 10 40 20 150 5 30 40
JUL 130 30 10 20 5 20 480 40 20 JUL 50 90 20 60 30 300 5 10 40
AUG 120 50 40 40 20 20 150 60 10 AUG 60 40 10 60 20 140 5 10 50
SEP SEP
OCT 230 80 60 60 120 40 180 60 60 OCT 70 170 40 70 30 130 10 10 50
NOV 70 10 10 20 20 10 50 20 20 NOV 20 70 10 30 20 80 10 10 20
DEC 130 20 20 30 70 30 80 20 50 DEC 20 50 10 30 10 20 5 20 20
mean 170 30 21 27 42 24 103 43 32 mean 38 66 14 43 19 134 6 15 33
std dev 64 22 16 13 35 16 136 20 23 std dev 19 40 10 16 8 83 2 8 13
median 130 30 20 20 20 20 40 40 20 median 40 70 10 40 20 140 5 10 40
max 240 80 60 60 120 50 480 70 60 max 70 170 40 70 30 300 10 30 50
min 70 10 5 10 5 10 10 20 5 min 10 20 5 20 5 20 5 10 10
43
Table 2.15 Chlorophyll a (mg/l) during 2018 at the Lower Cape Fear River Program stations.
NAV HB BRR M61 M54 M35 M23 M18 NC11 AC DP BBT IC NCF6
JAN 2 1 1 1 1 1 2 2 JAN 0 1 0 1 1 0
FEB 2 1 3 2 2 2 7 5 FEB 5 6 3 3 2 1
MAR 3 2 3 2 4 5 10 13 MAR 6 3 4 4 3 1
APR 1 1 1 1 1 2 3 3 APR 2 2 2 1 2 1
MAY 2 3 2 1 2 5 6 5 MAY 2 1 2 1 1 1
JUN 1 1 4 1 4 6 4 5 JUN 1 1 1 1 1 0
JUL 3 7 21 11 4 9 11 12 JUL 2 2 3 2 2 0
AUG 1 1 1 1 1 1 1 1 AUG 1 1 1 1 1 0
SEP SEP 2 3 1 1 1 7
OCT 2 3 2 2 2 1 2 3 OCT 2 2 1 11 7 13
NOV 2 2 2 2 3 3 2 4 NOV 2 2 1 1 1 2
DEC 3 3 2 1 2 1 1 6 DEC 2 2 2 2 1 1
mean 2 2 4 2 2 3 4 5 mean 2 2 2 2 2 2
std dev 1 2 6 3 1 3 4 4 std dev 2 1 1 3 2 4
median 2 2 2 1 2 2 3 5 median 2 2 2 1 1 1
max 3 7 21 11 4 9 11 13 max 6 6 4 11 7 13
min 1 1 1 1 1 1 1 1 min 0 1 0 1 1 0
ANC SAR GS NC403 PB LRC ROC NCF117 SC-CH B210 COL SR-WC 6RC LCO GCO SR BRN HAM
JAN 1 2 3 11 28 2 2 1 0 JAN 3 2 2 4 1 2 11 2 4
FEB 1 18 6 7 9 1 12 1 2 FEB 2 3 2 3 2 3 16 2 5
MAR 1 1 1 3 12 2 1 0 1 MAR 1 2 2 1 1 1 9 0 3
APR 4 2 3 5 11 5 3 1 12 APR 1 3 2 6 1 2 14 2 3
MAY 4 1 2 13 2 2 1 1 2 MAY 1 2 0 0 0 1 18 1 2
JUN 3 1 2 11 5 4 1 1 1 JUN 0 2 1 1 1 2 16 1 1
JUL 4 4 13 17 22 2 38 1 13 JUL 1 3 1 1 1 2 43 2 5
AUG 25 1 3 9 13 2 0 0 6 AUG 0 2 1 1 1 1 4 1 1
SEP SEP
OCT 4 1 20 39 18 7 7 17 24 OCT 0 0 0 1 1 2 4 6 0
NOV 1 1 1 3 1 2 0 1 5 NOV 0 1 0 1 0 2 5 2 0
DEC 3 1 1 2 1 6 1 0 1 DEC 1 1 1 2 4 2 2 1 1
mean 5 3 5 11 11 3 6 2 6 mean 1 2 1 2 1 2 13 2 2
std dev 7 5 6 10 9 2 11 5 7 std dev 1 1 1 2 1 1 11 2 2
median 3 1 3 9 11 2 1 1 2 median 1 2 1 1 1 2 11 2 2
max 25 18 20 39 28 7 38 17 24 max 3 3 2 6 4 3 43 6 5
min 1 1 1 2 1 1 0 0 0 min 0 0 0 0 0 1 2 0 0
44
0
1
2
3
4
5
6
7
NC11 AC DP IC NAV HB BRR M61 M54 M35 M23 M18 NCF117 NCF6 B210 BBT
Ch
l
o
r
o
p
h
y
l
l
a
(mg/
L
)
Figure 2.7 Chlorophyll a at the Lower Cape Fear River Program mainstem stations,
1995-2017 versus 2018.
1995-2017
2018
45
Table 2.16 Fecal Coliform (cfu/100 mL) and Enterococcus (MPN) during 2018 at the Lower Cape Fear River Program stations.
ENTEROCOCCUS
NC11 AC DP IC NCF6 NAV HB BRR M61 M54 M35 M23 M18
JAN 19 19 28 37 5 5 91 JAN 31 51 5 10 5 20
FEB 390 290 55 172 10 46 55 FEB 22 57 94 75 67 101
MAR 28 28 55 10 37 546 10 MAR 97 85 63 20 10 96
APR 46 5 28 28 55 46 46 APR 5 5 10 5 5 5
MAY 19 73 73 19 73 10 82 MAY 20 41 41 62 20 20
JUN 14 23 41 32 43 37 37 JUN 30 31 20 26 89 5
JUL 46 181 5 19 230 19 46 JUL 10 31 5 5 5 5
AUG 127 181 46 100 5 127 91 AUG 20 10 10 5 10 10
SEP 19 28 46 91 280 SEP
OCT 55 37 82 145 819 28 10 OCT 10 20 20 5 5 5
NOV 55 55 46 5 109 91 28 NOV 5 10 5 5 10 5
DEC 320 300 109 91 37 5 5 DEC 20 20 85 31 31 5
mean 95 102 51 62 142 87 46 mean 25 33 33 23 23 25
std dev 121 103 26 54 221 149 30 std dev 24 23 32 24 27 35
max 390 300 109 172 819 546 91 max 97 85 94 75 89 101
min 14 5 5 5 5 5 5 min 5 5 5 5 5 5
Geomean 50 55 42 39 51 34 32 Geomean 17 25 19 13 13 12
ANC SAR GS NC403 PB LRC ROC NCF117 SC-CH B210 COL SRWC 6RC LCO GCO SR BRN HAM
JAN 37 28 5 5 19 37 109 163 340 JAN 37 172 190 530 340 145 210 91 728
FEB 10 82 37 37 5 19 163 240 64 FEB 28 19 55 55 37 37 28 73 1,180
MAR 109 145 82 163 190 28 728 46 73 MAR 19 46 37 64 28 73 73 136 199
APR 530 210 46 163 73 136 340 28 154 APR 19 37 440 1,460 480 199 240 310 1,550
MAY 37 145 163 1,270 340 163 410 37 200 MAY 64 109 28 55 290 154 127 136 217
JUN 91 145 28 260 235 73 340 260 136 JUN 55 118 37 73 73 100 64 240 91
JUL 240 37 127 200 60,000 320 910 10 217 JUL 55 109 210 136 570 19 430 520 217
AUG 250 270 370 250 1,730 355 340 37 270 AUG 100 728 19 460 370 300 163 819 260
SEP SEP
OCT 37 144 250 270 3000 480 172 1,180 480 OCT 28 10 100 200 91 127 172 270 1,000
NOV 28 73 19 82 24 37 240 46 145 NOV 82 82 136 91 73 230 118 320 430
DEC 19 28 5 5 5 5 64 10 5 DEC 37 28 28 19 19 28 37 37 55
mean 126 119 103 246 5,966 150 347 187 189 mean 48 133 116 286 216 128 151 268 539
std dev 151 74 112 337 17,111 155 248 326 129 std dev 25 194 121 405 191 85 110 219 479
max 37 270 370 1,270 60,000 480 910 1,180 480 max 100 728 440 1,460 570 300 430 819 1,550
min 10 28 5 5 5 5 64 10 5 min 19 10 19 19 19 19 28 37 55
Geomean 65 93 49 99 172 73 267 66 127 Geomean 41 67 72 133 123 95 114 191 340
46
0
10
20
30
40
50
60
70
80
90
100
NC11 AC DP IC NAV HB NCF117 NCF6 B210 BRR M61 M54 M35 M23 M18
Fe
c
a
l
C
o
l
i
f
o
r
m
B
a
c
t
e
r
i
a
(
C
F
U
/
1
0
0
m
L
)
Figure 2.8 Geometric Mean Fecal Coliform (NC11-B210) and Enterococcus (BRR-M18) at
the LCFRP mainstem stations, 1996-2017 (Entero 2012-2017 ) vs. 2018.
1996-2017
2018
47