water quality in the withers swash basin ...myrtle beach, s.cv august 1991 through june 1993..... 37...
TRANSCRIPT
WATER QUALITY IN THE WITHERS SWASH BASIN, WITH EMPHASIS ON ENTERIC BACTERIA, MYRTLE BEACH, SOUTH CAROLINA, 1991-93
By Wladmir B. Guimaraes
U.S. GEOLOGICAL SURVEY Water-Resources Investigations Report 95-4125
Prepared in cooperation with the
CITY OF MYRTLE BEACH
Columbia, South Carolina 1995
U.S. DEPARTMENT OF THE INTERIOR
BRUCE BABBITT, Secretary
U.S. GEOLOGICAL SURVEY
Gordon P. Eaton, Director
For additional information write to: Copies of this report can be purchased from:
U.S. Geological SurveyDistrict Chief Earth Science Information CenterU.S. Geological Survey Open-File Reports SectionStephenson Center- Suite 129 Box 25286, Mail Stop 517720 Gracern Road Denver Federal CenterColumbia, SC 29210-7651 Denver, CO 80225
CONTENTS
Page
Abstract .......................................................................... 1
Introduction....................................................................... 1Purpose and scope........................................................... 3Description of study area ..................................................... 3Previous investigations....................................................... 4Acknowledgments........................................................... 4
Data-collection methods ............................................................ 4Streamflow ................................................................. 6Water quality ............................................................... 6Bacteria .................................................................... 8
Water quality in the Withers Swash Basin ............................................. 9Physical properties, major ions, nutrients, trace elements,
and cyanide ............................................................. 9Organic compounds ........................................................ 19Enteric bacteria............................................................. 32Best management practices for improved water quality.......................... 46
Summary ........................................................................ 47
Selected references ................................................................ 49
Appendix 1: Results of physical property, oxygen demand, total organic carbon, total residue, turbidity, hardness, major ion, and alkalinity analyses of water samples collected at three gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992........................................................ 73
Appendix 2: Results of nutrient analyses of water samples collected at three gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992 ......................................... 77
Appendix 3: Results of trace element and cyanide analyses of water samples collected at three gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992 .............................. 80
Appendix 4: Results of volatile organic compound analyses of water samples collected at three gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992 .............................. 83
CONTENTS-Continued i
Page
Appendix 5: Results of acid- and base/neutral-extractable organic compound analyses of water samples collected at three gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992........................................................ 91
Appendix 6: Results of selected pesticide analyses of water samples collected at three gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992 ......................................... 98
ILLUSTRATIONS
Figure 1. Map showing location of the Mainstem and KOA subbasins of the Withers Swash Basin, and gaging stations in the study area, Myrtle Beach, S.C. ...................................................... 2
2. Graph showing relation of fecal coliform and fecal streptococcus bacteria counts to streamflow for station 021107380, Mainstem Branch of Withers Swash, Myrtle Beach, S.C., August 1991 through June 1993 ..................................................... 40
3. Graph showing relation of fecal coliform and fecal streptococcus bacteria counts to streamflow for station 021107385, KOA Branch of Withers Swash, Myrtle Beach, S.C., August 1991 through June 1993 ..................................................... 41
4. Map showing location of enteric-bacteria sampling sites inMyrtle Beach, S.C. ..................................................... 42
5. Diagram showing the enteric-bacteria sampling sites, the number of samples collected, and the number of samples with enteric-bacteria counts greater than 2,000 colonies per 100 milliliters, Withers Swash area, Myrtle Beach, S.C, August 1991 through June 1993.............. 43
6. Diagram showing the enteric-bacteria sampling sites, the number of samples collected, and the number of samples with enteric-bacteria counts greater than 5,000 colonies per 100 milliliters, Withers Swash area, Myrtle Beach, S.C., August 1991 through June 1993.................... 44
7. Diagram showing the enteric-bacteria sampling sites, the number of samples collected, and the number of samples with enteric-bacteria counts greater than 10,000 colonies per 100 milliliters, Withers Swash area, Myrtle Beach, S.C., August 1991 through June 1993.................... 45
IV
TABLES
Page
Table 1. Summary of data collection at the gaging stations in the Withers Swash Basin, Myrtle Beach, S.C. ..........................
2. Summary of processing and preservation methods for the analysis of inorganic compounds in water samples collected at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C. .............................. 7
3. Summary of processing and preservation methods for the analysis of organic compounds in water samples collected at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C. .............................. 8
4. Physical, bacteria, and inorganic analyses made on water samples collected at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992................. End of report
5. Organic compounds and detection limits for analyses made on water samples collected at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992 ................................................. End of report
6. Statistical summary of physical properties, oxygen demand, total organic carbon, residue, turbidity, hardness, alkalinity, and major ion concentrations in water samples collected at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C, September 1991 through August 1992................................. 10
7. Statistical summary of nutrient concentrations in water samples collected at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992........................... 13
8. Statistical summary of trace-element concentrations in water samples collected at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992 ........................................................... 15
9. Trace element, cyanide, asbestos, and dioxin compounds listed in the South Carolina Department of Health and Environmental Control Criteria for Protection of Human Health and the maximum concentrations detected within the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992 .............. 18
10. Statistical summary of volatile organic compounds, acid- and base/neutral-extractable organic compounds, and pesticides in water samples collected at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992 ........................................................... 20
TABLES-Continued
Page
11. Summary of organic compounds detected in water samples collected at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., and number of water samples in which concentrations exceed the South Carolina Department of Health and Environmental Control Human Health criteria, September 1991 through August 1992 ................ 23
12. Volatile organic compounds listed in the South Carolina Department of Health and Environmental Control Criteria for Protection of Human Health and the maximum concentrations detected within the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992 ................................................... 25
13. Acid-extractable organic compounds listed in the South Carolina Department of Health and Environmental Control Criteria for Protection of Human Health and the maximum concentrations detected within the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992 ..................................... 27
14. Base/neutral-extractable organic compounds listed in the South Carolina Department of Health and Environmental Control Criteria for Protection of Human Health and the maximum concentrations detected within the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992 .................... 28
15. Pesticide and PCB compounds listed in the South CarolinaDepartment of Health and Environmental Control Criteria forProtection of Human Health and the maximum concentrationsdetected within the Withers Swash Basin, Myrtle Beach, S.C.,September 1991 through August 1992 ..................................... 30
16. Results of gas chromatograph/flame ionization detector analyses of water samples collected in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992........................... 31
17. Results of National Institute of Standards and Technology library search of chromatograms from gas chromatograph/flame ionization detector analyses of water samples collected from the Withers Swash Basin, Myrtle Beach, S.C., September 1991 ........................................................ 33
18. Summary of sampling conditions and enteric-bacteria counts for station 021107380, Mainstem Branch of Withers Swash, Myrtle Beach, S.C., August 1991 through June 1993.......................... 35
vi
TABLES-Continued
Page
19. Summary of sampling conditions and enteric-bacteria counts for station 021107385, KOA Branch of Withers Swash, Myrtle Beach, S.CV August 1991 through June 1993.......................... 37
20. Results of bacteria sampling at various locations within the Withers Swash Basin and in the Atlantic Ocean near the mouth of Withers Swash, Myrtle Beach, S.C., August 1991 through June 1993 ............................................ End of report
VII
CONVERSION FACTORS, VERTICAL DATUM, ABBREVIATED WATER-QUALITY UNITS,
AND ACRONYMS
Multiply By To obtain
Lengthinch (in.) 25.4 millimeter foot (ft) 0.3048 meter
Area square mile (mi2) 2.590 square kilometer
Flow cubic foot per second (ft3/s) 0.02832 cubic meter per second
Temperature in degrees Celsius (°C) can be converted to degrees Fahrenheit (°F) as follows:
°F = (1.8 x °C) + 32
Sea level: In this report, "sea level" refers to the National Geodetic Vertical Datum of 1929--a geodetic datum derived from a general adjustment of the first-order level nets of the United States and Canada, formerly called Sea Level Datum of 1929.
Specific conductance of water is expressed in microsiemens per centimeter (}iS/cm) at 25 degrees Celsius (25 °C).
Chemical concentration in water is expressed in milligrams per liter (mg/L) or micrograms per liter (ng/L).
Colonies per 100 milliliters is expressed as col/100 mL.
micrometer - jim.
VIII
CONVERSION FACTORS, VERTICAL DATUM, ABBREVIATED WATER-QUALITY UNITS,
AND ACRONYMS-Continued
Acronyms used in the tables and text of this report:
AA atomic absorption
AAS atomic absorption spectrometry
ABN acid and base/neutral
ADR automatic data recorder
AE atomic emission
BHC benzene hexachloride
BMP best management practices
DC direct current
DDD dichlorodiphenyldichloroethane
DDE dichlorodiphenyldichloroethylene
DDT dichlorodiphenyltrichloroethane
FID flame ionization detector
GC/FID gas chromatograph/flame ionization detector
GC/MS gas chromatograph/mass spectrometry
HPLC high-performance liquid chromatography
1C ion chromatography
ICP inductively coupled plasma
MF membrane filtration
NTU nephelometric turbidity unit
PCB polychlorinated biphenyls
PCN polychlorinated naphthalene
SCDHEC South Carolina Department of Health and Environmental Control
SFH shellfish harvesting
TCDD tetrachlorodibenzodioxin
USDA U.S. Department of Agriculture
USEPA U.S. Environmental Protection Agency
USGS U.S. Geological Survey
WATSTORE Water Data Storage and Retrieval System
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
ix
WATER QUALITY IN THE WITHERS SWASH BASIN, WITH EMPHASISON ENTERIC BACTERIA, MYRTLE BEACH,
SOUTH CAROLINA, 1991-93
By Wladmir B. Guimaraes
ABSTRACT
Water samples were collected in 1991-93 from Withers Swash and its two tributaries (the Mainstem and KOA Branches) in Myrtle Beach, S.C, and analyzed for physical properties, organic and inorganic constituents, and fecal coliform and streptococcus bacteria. Samples were collected during wet- and dry-weather conditions to assess the water quality of the streams before and after storm runoff.
Water samples were analyzed for over 200 separate physical, chemical, and biological constituents. Concentrations of 11 constituents violated State criteria for shellfish harvesting waters, and State Human Health Criteria. The 11 constituents included concentrations of dissolved oxygen, arsenic, lead, cadmium, mercury, chlordane, dieldrin, 1,1,1-trichloroethane, 1,1-dichloroethylene, trichloroethylene, and fecal coliform bacteria.
Water samples were examined for the presence of enteric bacteria (fecal coliform and fecal streptococcus) at 46 sites throughout the Withers Swash Basin and 5 sites on the beach and in the Atlantic Ocean. Water samples were collected just upstream from all confluences in order to determine sources of bacterial contamination. Temporally and spatially high concentrations of enteric bacteria were detected throughout the Withers Swash Basin; however, these sporadic bacteria concentrations made it difficult to determine a single source of the contamination. These enteric bacteria concentrations are probably derived from a number of sources in the basin including septic tanks, garbage containers, and the feces of waterfowl and domestic animals.
INTRODUCTION
The City of Myrtle Beach is a resort area located in the northern part of coastal South Carolina (fig. 1). Rapid growth in the area has caused rural land to'be replaced by residential homesites, hotels, motels, shopping centers, paved parking areas, and other facilities. The increase in population growth and urbanization has resulted in a decrease in pervious land for infiltration of rainfall, and an increase in the potential for point- and nonpoint-source pollution on the land surface and in watercourses. Many pollutants are primarily anthropogenic in origin and include a variety of organic debris, sediments, petroleum products, and potentially toxic compounds such as trace elements and pesticides. Most of these pollutants are assumed to be produced in large volumes in the Myrtle Beach area during the summer months because of the large seasonal population and motor traffic associated with tourism, the largest industry in the area.
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The Withers Swash Basin is a large drainage basin in the City of Myrtle Beach, S.C. The basin covers approximately 4.1 mi2 (Espy, Huston & Associates, Inc., 1988, p. 2) and includes industrial, residential, commercial, agricultural, recreational, and undeveloped land uses.
As part of a long-term water-quality management plan, the City of Myrtle Beach foresees developing the Withers Swash Basin into a commercial area. Because of concerns abou* water quality in the Withers Swash Basin, the U.S. Geological Survey (USGS), in cooperation with the City of Myrtle Beach, initiated an investigation during the summer months of 1991, 1992, and 1993 to characterize the chemical, physical, and biological quality of streamflow in the Withers Swash Basin and to identify, if possible, the principal sources of enteric bacteria contamination.
Purpose and Scope
The purpose of this report is to present data collected between 1991 and 1993 that characterizes the water quality of the Withers Swash Basin in Myrtle Beach, S.C. Data collected for this investigation reflect base- and high-flow water-quality sampling and intensive bacteria sampling. Specifically, the report includes discussions of the following data: (1) streamflow, (2) rainfall amounts, (3) values of physical properties, (4) inorganic constituent concentrations, and (5) organic compound concentrations. The report also extensively discusses results of a large-scale sampling effort for documentation of enteric bacteria counts in the Withers Swash Basin and the near-shore Atlantic Ocean. Discussions of the data are limited to statistical characterization of analytical results and constituents that violated South Carolina Department of Health and Environmental Control (SCDHEC) Quality Standards for Shellfish Harvesting (SFH) waters and Criteria for Protection of Human Health (South Carolina Department of Health and Environmental Control, 1993). A discussion of best management practices that reduce nonpoint-source pollution in the basin also is included.
The Criteria for class SFH waters and for Protection of Human Health (hereafter referred to as Human Health Criteria) are used as a standard for comparison purposes. Although tli e most current standards and criteria (1993) were used, they are subject to revision by State regulatory agencies. The SCDHEC publishes other criteria that were not used in this report. These include the Water-Quality Criteria Based on Organoleptic Data (Prevention of Undesirable Tarte and Odor) and the Criteria to Protect Aquatic Life (South Carolina Department of Health and Environmental Control, 1993), a generally more stringent criteria for all constituents except arsenic.
Description of Study Area
The Withers Swash Basin is characterized by relatively flat coastal topography. Elevations within the basin range from sea level at the mouth of Withers Swash, where it empties into the Atlantic Ocean, to about 30 ft above sea level in the upper reaches of the basin. The soils within the basin are classified as Brookman-Bladen and Lakeland-Leon-Newhan. Brookman-Bladen soils have a loamy surface layer with a clayey subsoil and are poorly drained. Lakeland-Leon- Newhan soils are sandy throughout and poorly drained (U.S. Department of Agriculture, 1986).
The Mainstem and KOA Branches of Withers Swash converge at a natural tidal basin between 5th Avenue South and Withers Swash Drive; this tidal basin discharges from Withers Swash to the Atlantic Ocean near Grand Strand Amusement Park (fig. 1). The Mainstem Branch
has two major tributaries, M-l and M-2; these two tributaries converge with the Mr ins tern Branch just upstream of Broadway Street. The Mainstem and KOA subbasins are located north and south, respectively, of Withers Swash.
The Mainstem subbasin is more urbanized than the KOA subbasin. The Mrinstem subbasin drains an area that includes commercial, single- and multi-family residential, and undeveloped land uses. In addition to these land uses, the KOA subbasin also includes some industrial land use.
Previous Investigations
Espy, Huston & Associates, Inc., (1988) discussed 1972 and 1976 studies that indicated that Myrtle Beach storm-water runoff contained high enteric-bacteria counts. Moore, Gardner & Associates, Inc. completed a study in 1980 to determine the magnitude of water-quality problems in Withers Swash. The study identified water-quality problems, and recommended solutions to reduce the amount of pollutants entering the ocean from storm-water runoff. These solutions included many engineered options, such as the discharging of storm water into the nearby Intracoastal Waterway, and discharges to the Atlantic Ocean through a diffuser pipe.
AcknowledgmentsThe author is grateful to the personnel of the City of Myrtle Beach, S.C., for providing
storm-sewer maps, topographic maps, reports and materials from previous studies, and technical support. Steve Moore, Street Superintendent, is acknowledged for his assistance in delineating the drainage areas of the Mainstem and KOA subbasins.
DATA-COLLECTION METHODS
Data collection included streamflow, rainfall amounts, and water-quality and bacteria sampling, although not all these types of data were gathered at each station. The water-quality data collected included measurements of physical properties, chemical analysis (inorganic and organic constituents), and bacterial data (fecal coliform and fecal streptococcus bacteria).
Three gaging stations in the Withers Swash Basin (fig. 1), each equipped with an automatic data recorder (ADR), continuously recorded water levels at 5-minute intervals. Thes^ three USGS stations were 021107380 (Mainstem Branch of Withers Swash at Broadway Street), 021107385 (KOA Branch of Withers Swash near 10th Avenue South), and 021107388 (Withers Swash at U.S. Highway 17), and will be referred to as the gaging stations on the Mrinstem Branch, KOA Branch, and Withers Swash, respectively, when discussing data collection in the study area. Information on the stations and the type of data collected at each station are P«ted in table 1. Rainfall also was collected at two stations, 334149078530800 (rain gage behind Chapin Ace Hardware near 10th Avenue North), and 021107385 (KOA Branch near 10th Avenue South) (fig. 1). The latter rain gage was located near the stage gage on the KOA Branch. Nations 334149078530800 and 021107385 recorded rainfall at 5-minute intervals in the Mainstem and KOA subbasins, respectively.
Table 1 .--Summary of data collection at the gaging stations in the Withers Swash Basin, Myrtle Beach, S.C.
[USGS, U.S. Geological Survey; B, bacteria; Q, streamflow; St, stage (water level); O, organic; I, inorganic; P, physical properties; Ave., avenue; S, south; R, rainfall; N, north]
USGS station number(fig. 1)
021107380
021107385
021107385
021107388
334149078530800
Station name
Mainstem of WithersSwash at BroadwayStreet, Myrtle Beach,S.C.
KOA Branch ofWithers Swash near10th Ave. S., MyrtleBeach, S.C.
KOA Branch ofWithers Swash near10th Ave. S., MyrtleBeach, S.C.
Withers Swash atHighway 17, MyrtleBeach, S.C.
Rain gage behindChapin AceHardware near 1 0thAve. N., MyrtleBeach, S.C.
Sampling dates
08/01/9109/10/9109/19/9109/20/9109/24/9106/04/9206/15/9207/18/9207/20/9208/03/9208/04/9208/05/9206/22/93
08/01/9109/10/9109/19/9109/20/9109/24/9111/08/9106/04/9207/18/9207/20/9208/03/9206/22/93
08/01/91through05/01/93
09/19/9109/20/9109/24/9106/04/9206/15/9206/16/9208/05/9206/22/93
08/01/91through05/01/93
Type of data collected
B, Q, StB, Q, StB, Q, StB, Q, StB, Q, St, O, I,B, Q, StB, Q, StB, Q, StB, Q, St, 0, 1,B, Q, St, O, I,B, Q, StB, Q, StB, Q, St
B, Q, StB, Q, StB, Q, StB, Q, StB, Q, St, O, I,B, Q, StB, Q, StB, Q, StB, Q, St, 0, I,B, Q, St, 0, I,B, Q, St
R
B,StB, StB, St, O, I, PB, StB, StB, StB, StB, St
R
P
PP
P
PP
The sampling strategy was designed to characterize water quality under bare-flow conditions and during storm-water runoff, with emphasis on the bacterial water quality of the streams. Water samples were collected at the gaging stations during periods of base flow prior to rainfall to determine the concentrations of selected water-quality constituents prior to storm runoff. Runoff-water samples were collected at the gaging stations prior to peak, during peak, and following peak streamflow. After an initial runoff was sampled at Withers Swash, sampling was shifted to the upstream gaging stations on the Mainstem and KOA Branches, because Withers Swash was constantly influenced by the tides. Samples for fecal coliform and fecal streptococcus bacteria analysis were collected at 51 sites throughout the Withers Swash Ba^'n, on the beach, and at its confluence with the Atlantic Ocean, at selected streamflow rates in an effort to determine sources of enteric-bacteria contamination.
StreamflowStreamflow was determined at gaging stations on the Mainstem and KOA Branches using a
stage-discharge relation as described by Kennedy (1984). The stage-discharge relation at Withers Swash was not developed because of streamflow reversal at high tides, but water levels at the station were used to indicate tidal influence in the basin. During the runoff event of September 24, 1991, the stage-discharge relation at the Mainstem Branch was tidally affected, and the streamflow was measured using stream-gaging techniques modified from Rantz and others (1982). The modifications included taking velocity readings at less than 20 observation verticals in the measurement cross section, because the stream was narrow. Velocities were determined at 20-second, rather than 40-second intervals, because the stage was changing rapidly.
Water QualifyWater-quality samples were collected at gaging stations and analyzed for selected
inorganic and organic constituents, physical properties, and bacteria. Samples were collected at the center of the streamflow, processed, and preserved. To ensure representative water-quality sampling, physical properties including water temperature, pH, specific conductance, and dissolved-oxygen concentrations were measured at each site when the samples were collected.
Procedures used in this study for water-quality sampling are described in Guy and Norman (1970), Stevens and others (1975), Wershaw and others (1983), and Fishmen and Friedman (1985). Sample-volume requirements, processing and preservation methods, and analysis of inorganic constituents are summarized in table 2, and analysis of organic constituents and bacteria are summarized in table 3. All analyses were done by the USGS National Water Quality Laboratory in Denver, Colo., except for enteric-bacteria analyses, which were done by the USGS in Columbia, S.C.
Inorganic analyses included physical properties such as water temperature, pH, specific conductance, and dissolved-oxygen concentrations, and constituents such as total nitrogen and phosphorus (nutrients), major ions, trace elements, and cyanide. Organic analyses included gas chromatograph/mass spectrometric (GC/MS) quantification of detectable concentrations of acid- and base/neutral-extractable (ABN) and volatile compounds. Selected GC/MS spectrograms for ABN and volatile constituents were further researched using spectral libraries maintained by the National Institute of Standards and Technology. Water samples also were analyzed for the presence of organochlorine pesticide compounds. Analytical methods, reporting units, and detection limits are listed in tables 4 and 5 at the end of the report.
Table 2.~Summary of processing and preservation methods for the analysis of inorganic compounds in water samples collected at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C.
[L, liters; °C, degrees Celsius; ml_, milliliters; ICP, inductively coupled plasma; <, less than; AA, atomic absorption; >, greater than; urn, micrometers]
Bottle volume Analyses made Filtered' Preservation method
1 L Alkalinity Turbidity Total suspended solids
No Chilled to 4 °C
500 mL Sulfate, dissolved Chloride, dissolved
Yes Chilled to 4 °C
250 mL (acid rinsed) Total trace elementsusing ICP method
No 1 ml HNO3 to pH < 2; chilled to 4 °C
250 mL (acid rinsed) Dissolved traceelements using ICPmethodSodium, dissolved
Yes Add HNO3 to pH < 2; chilled to 4 °C
500 mL (acid rinsed) Magnesium, dissolvedCalcium, dissolved Potassium, dissolved
Yes Add HNO3 to pH < 2; chilled to 4 °C
500 mL (acid rinsed) Total trace elementsusing AA method
No Add HNO3 to pH < 2; chilled to 4 °C
250 mL (amber) Cyanide No AddNaOHtopH>12; chilled to 4 °C
250 mL (amber) Nutrients No Add H2SO4 to pH < 2; chilled to 4 °C
'All bottles are clear polyethylene plastic unless otherwise specified. 2Filtered through 0.45 um pore-size filter.
Table ^.--Summary of processing and preservation methods for the analysis of organic compounds in water samples collected at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C.
[L, liters; °C, degrees Celsius; mL, milliliters]
Bottle volume 1 Analyses made FilteredPreservation technique
Four 1 L
125 mL
Two 40 mL septum vials
200 mL
200 mL
Acid- and base/neutral- extractable organic compounds
Organochlorine pesticides
Total organic carbon
Volatile organic compounds
Fecal coliform bacteria
Fecal streptococcus bacteria
No
No
No
No
No
No
Chilled to 4 °C
Chilled to 4 °C
Chilled to 4 °C
Chilled to 4 °C
Chilled to 4 °C
Chilled to 4 °C
'All bottles are glass, cleaned of all organic contaminants, and baked at 300 °C overnight. Lids are lined with teflon.
Bacteria
Samples for fecal coliform and fecal streptococcus bacteria analyses were collected during wet- and dry-weather periods at 46 sites near confluences along stream reaches within the Withers Swash Basin and an additional five sites outside the basin. Three of the five sit?s were located in the ocean near the mouth of Withers Swash and two sites were located north of Withers Swash at a storm-water-discharge culvert on the beach. The membrane filtration (MF) method of analysis was used because its direct enumeration yields statistically better results than other methods (Britton and Greeson, 1988). The MF method also can be done in the field, and the results are available within 24 to 48 hours after incubation. The ideal colony count for fecal coliform and fecal streptococcus is 20 to 60 col/100 mL and 20 to 100 col/100 mL, respectively. To obtain ideal counts of colonies, the range of enteric-bacteria counts should be known in order to prepare a proper dilution. Because enteric-bacteria counts were not known initially, selected dilutions were occasionally not of proper dilution; therefore, some counts were determined from a non-ideal count of colonies. The procedures used in sampling, filtering, incubating, and counting colonies are described by Britton and Greeson.
WATER QUALITY IN THE WITHERS SWASH BASIN
The results of over 200 chemical, physical, and biological constituents analyzed in water samples collected in the Withers Swash Basin are discussed in this section. Concentrations are compared to specific criteria listed in State criteria for class SFH waters and State Human Health Criteria. These criteria are used to evaluate water-quality data in two basic groups of characteristics: (1) physical properties, major ions, nutrients, trace elements, and cyanide; and (2) volatile organic, acid- and base/neutral-extractable organic, and organochlorine perticide compounds. Discussion of analytical results are confined to the USGS gaging stations on the Mainstem and KOA Branches where the streams are not influenced by tides, except for the event of September 24,1991, where samples also were collected in Withers Swash. Water quality of the Withers Swash Basin varied from well within to violating State criteria. Most of the violations of criteria occurred during storms.
Water samples collected at Withers Swash showed that high concentrations detected at the upstream stations on the Mainstem and KOA Branches were attenuated by the tidal basin. The tidal basin acts as a detention pond, in which some nonconservative constituents settle out of the water column. Other nonconservative constituents are degraded by biological processes. Conservative constituents that do not settle out are diluted within the tidal basin. Although some constituents were detected at Withers Swash, the concentrations were far below concentrations detected at the upstream stations and did not violate State criteria.
Fecal coliform and fecal streptococcus bacteria were examined at 15 sites on the Mainstem and KOA Branches on August 1, 1991, during dry-weather conditions. Enteric-bacteria counts were high and spatially sporadic. Eleven of the same fifteen sites were sampled on September 10, 1991, during dry-weather conditions. The results of the two sampling events indicated that the high enteric-bacteria counts also were temporally sporadic. Because these high counts were temporally and spatially sporadic, 149 water samples were synoptically collected at 51 sites throughout the Withers Swash Basin, on the beach, and in the Atlantic Ocean near the mouth of Withers Swash, and examined for enteric bacteria.
Physical Properties. Maior Ions. Nutrients. Trace Elements, and Cvanide
The water samples collected in the Withers Swash Basin were examined for physical properties, major ions, nutrients, trace elements, and cyanide (tables 6, 7, and 8; appendixes 1, 2, and 3). Results indicate that nutrients and trace elements were detected at the gaging stations on the Mainstem and KOA Branches, and Withers Swash. Major ions were detected at the gaging stations on the Mainstem and KOA Branches, but no data on major ions were obtaired in Withers Swash. Instantaneous streamflows at the gaging stations during each sampling event also were determined.
Withers Swash Basin is classified as SFH waters by the SCDHEC (Zach Corontzer, oral commun., January 24, 1995). Class SFH waters are classified as tidal saltwaters protected for shellfish harvesting, suitable for primary- and secondary- contact recreation, fishing, cral^bing, and the survival and propagation of a balanced indigenous aquatic community of marine fauna an flora (South Carolina Department of Health and Environmental Control, 1993).
Tabl
e Q
.-Sta
tistic
al s
umm
ary
of p
hysi
cal p
rope
rties
, ox
ygen
dem
and,
tot
al o
rgan
ic c
arbo
n, r
esid
ue,
turb
idity
, ha
rdne
ss,
alka
linity
, and
maj
or io
n co
ncen
tratio
ns in
w
ater
sam
ples
col
lect
ed a
t gag
ing
stat
ions
in th
e W
ither
s S
was
h Ba
sin,
Myr
tle B
each
, S.
C.,
Sep
tem
ber
1991
thr
ough
Aug
ust
1992
[°C
, de
gree
s C
elsi
us;
^iS/
crn,
mic
rosi
emen
s pe
r cen
timet
er;
mg/
L, m
illig
ram
s pe
r lit
er; N
TU,
neph
elom
etric
turb
idity
uni
ts; <
, le
ss th
an;
--, n
o da
ta]
WA
T-
STO
RE
1 pa
ra
met
erco
de
0001
0
0040
3
0009
5
9009
5
0030
0
0030
1
0031
0
Con
stitu
ent
or p
rope
rty
Wat
er
°Cte
mpe
ratu
re
pH,
lab
Sta
ndar
d
Spe
cific
|iS
/cm
cond
ucta
nce,
field
Spe
cific
^i
S/c
mco
nduc
tanc
e,la
b
Oxy
gen,
m
g/L
diss
olve
d
Oxy
gen,
P
erce
ntdi
ssol
ved
perc
ent
satu
ratio
n
Bio
chem
ical
m
g/L
oxyg
ende
man
d
Sta
tion
021
1073
80
(Mai
nste
m B
ranc
h)
Number 12 12 12 12 12 12 9
i
Maximum 28
.0 8.1
629
657 6.
0
74.2
20.5
Minimum 23
.0 7.2
88 98 3.5
40.9 6.5
1
Median
25.3 7.5
385
434 4.
5
53.7
11.5
Sta
tion
021
1 073
85
Sta
tion
021
1 073
88
(KO
A B
ranc
h)
(With
ers
Sw
ash)
1
| |
.§
1
§ |
.1
| 1
|
"S
| -I
|
"S
12
27.0
23
.5
25.3
3
27.0
25
.0
25.0
12
10.4
3.
2 7.
3 3
7.9
7.7
7.7
12
1,20
0 82
32
6 3
66,0
00
46,0
00
46,2
00
12
1,20
0 87
33
0 3
45,2
00
36,6
00
38,0
00
12
5.3
2.6
4.4
3 7.
6 5.
9 6.
2
12
66.6
31
.4
52.9
3
113
85
89
9 23
.5
6 9.
5 3
12
6 7
Tabl
e 6.
-Sta
tistic
al s
umm
ary
of p
hysi
cal p
rope
rties
, ox
ygen
dem
and,
tot
al o
rgan
ic c
arbo
n, r
esid
ue,
turb
idity
, ha
rdne
ss,
alka
linity
, an
d m
ajor
ion
conc
entra
tions
in
wat
er s
ampl
es c
olle
cted
at g
agin
g st
atio
ns in
the
With
ers
Sw
ash
Basi
n, M
yrtle
Bea
ch,
S.C
., S
epte
mbe
r 19
91 t
hrou
gh A
ugus
t 79
92--C
ontin
ued
[°C
, de
gree
s C
elsi
us;
|aS/
cm,
mic
rosi
emen
s pe
r cen
timet
er;
mg/
L, m
illig
ram
s pe
r lit
er;
NTU
, ne
phel
omet
ric tu
rbid
ity u
nits
; <,
less
than
; --,
no
data
]
WA
T-
STO
RE
1 pa
ra
met
erco
de
0034
0
0068
0
0051
5
0053
0
7030
0
0007
6
0090
0
9041
0
Con
stitu
ent
. . .
or p
rope
rty
Che
mic
al
mg/
Lox
ygen
de
man
d
Tota
l org
anic
m
g/L
carb
on
Res
idue
at
mg/
L 10
5°C
,di
ssol
ved
Res
idue
at
mg/
L 10
5°C
,su
spen
ded
Sol
ids
resi
due
mg/
L a
t18
0°C
,di
ssol
ved
Turb
idity
N
TU
Har
dnes
s,
mg/
L to
tal
Alk
alin
ity
mg/
L as
CaC
o3
Sta
tion
021
1073
80
(Mai
nste
m B
ranc
h)
1 |
| .i-
E
-E
E
-o§
X
"F
0)i
| 1
5
11
99
15
30
8 42
10
17
4 39
9 97
25
7
12
231
<1
29
8 37
0 68
30
1
4 67
5.
5 39
.5
8 22
0 35
16
5
12
272
37
152
Number
12 7 5 12 7 5 7 12
Sta
tion
021
1 073
85
Sta
tion
021
1 073
88
(KO
A B
ranc
h)
(With
ers
Sw
ash)
1 1
5 1
| I
S.E
E
=0
c
.E
E
=5
3 i
1
1
3 i
32
S
^
z
2
S
2
120
23
60
3 81
0 62
0 73
0
50
13
19
213
90
129
3 34
,700
28
,100
29
,900
168
1 41
3
14
2 8
640
73
222
60
3 7
3 10
2.
2 8.
4
240
28
67
232
<1
43
3 12
9 11
6 11
7
Tabl
e Q
.-Sta
tistic
al s
umm
ary
of p
hysi
cal p
rope
rties
, ox
ygen
dem
and,
tot
al o
rgan
ic c
arbo
n, r
esid
ue,
turb
idity
, ha
rdne
ss,
alka
linity
, an
d m
ajor
ion
conc
entra
tions
in
wat
er s
ampl
es c
olle
cted
at g
agin
g st
atio
ns in
the
With
ers
Swas
h Ba
sin,
Myr
tle B
each
, S.
C.,
Sep
tem
ber
1991
thr
ough
Aug
ust
7992
--Con
tinue
d
[°C
, deg
rees
Cel
sius
; |iS
/cm
, m
icro
siem
ens
per c
entim
eter
; m
g/L,
mill
igra
ms
per
liter
; NTU
, ne
phel
omet
ric tu
rbid
ity u
nits
; <,
less
than
; --,
no d
ata]
WAT
- S
TOR
E1
para
m
eter
co
de
0091
5
0092
5
0093
0
0093
5
0094
0
0094
5
7030
1
Con
stitu
ent
or p
rope
rty
Cal
cium
,di
ssol
ved
Mag
nesi
um,
diss
olve
d
Sod
ium
,di
ssol
ved
Pot
assi
um,
diss
olve
d
Chl
orid
e,di
ssol
ved
Sul
fate
,di
ssol
ved
Sol
ids,
sum
of
diss
olve
dco
nstit
uent
s
Sta
tion
02 11
073
80
Sta
tion
0211
0738
5 S
tatio
n 02
1107
388
(Mai
nste
m B
ranc
h)
(KO
A B
ranc
h)
(With
ers
Swas
h)
fcllsfcllsfc!
I s
fE
l-lfE
lS
fE
II
5x'cO
>§x'c<
i>
§x
'c
<i>
i3izi.||zi|
i
:>
mg
/L
8 83
13
61
.5
7 88
10
24
mg
/L
8 3.
4 .6
8 2.
8 7
6.1
.72
1.7
mg/L
8
50
4.0
35
7 18
0 4.
5 34
mg/L
8
4.1
1.1
2.8
7 4.
4 2.
1 2.
7
mg/
L 8
45
4.2
35
7 27
0 4.
7 68
mg
/L
8 34
8.
2 28
7
53
7.6
33
mg/
L 8
353
54.0
25
8 6
544
46
191
'Nat
iona
l W
ater
Dat
a St
orag
e an
d R
etri
eval
Sys
tem
of t
he U
.S. G
eolo
gica
l Su
rvey
.
Tabl
e 7.
--S
tatis
tical
sum
mar
y of
nut
rient
con
cent
ratio
ns in
wat
er s
ampl
es c
olle
cted
at g
agin
g st
atio
ns in
the
With
ers
Sw
ash
Bas
in,
Myr
tle B
each
, S.
C.,
Sep
tem
ber
1991
thr
ough
Aug
ust
1992
[All
conc
entr
atio
ns in
mill
igra
ms
per
liter
; <,
les
s th
an;
--,
no d
ata]
WA
T-
ST
OR
E1
para
m
eter
co
de
0060
0
0060
5
0061
0
0061
5
0062
0
0062
5
0063
0
7134
5
Con
stitu
ent
o3 & u
Z
Nitr
ogen
, 12
tota
l
Nitr
ogen
, 1 2
orga
nic,
tot
al
Nitr
ogen
, 1 2
NH
3, t
otal
Nitr
ogen
, 12
nitr
ite,
tota
l
Nitr
ogen
, 1 2
nitr
ate,
tot
al
Nitr
ogen
, 1 2
orga
nic
+N
H3,
tot
al
Nitr
ogen
, 12
NO
2+N
O3,
tota
l
Nitr
ogen
, 1 2
NH
3, t
otal
Sta
tion
021
1073
80
(Mai
nste
m B
ranc
h)
Maximum
3.3
1.4 .2
8
.1 1.81
1.5
1.9 .0
0
| .1
E
-Q
1 *
0.67
1.
05
.26
.57
.01
.13
.01
.02
.064
.2
9
.5
.65
.074
.3
40
.01
.1"
Number 12 12 12 12 12 12 12 12
Sta
tion
021
1073
85
(KO
A B
ranc
h)
Maximum
7.1
3.1
1.6 .0
7
3.13
3.9
3.20
2.1
Minimum
0.75 .3
4
.07
.01
,054
.60
,064
,09
Median
1.8 .9
1
.62
.03
.310
1.6 ,3
50
.30
Sta
tion
021
1073
88
(With
ers
Sw
ash)
s 1
1E
1
I=;
x
Fi
I i
-- 3 0.
35
0.33
3 .0
7 .0
5
3 .0
1 <.
01
.. 3 .4
0 .4
0
3 <.
05
<.05
3 .0
9 .0
6
Median
~ 0.34 .0
6
<.01
~
.40
<.05 .0
8
Tabl
e 7.
-Sta
tistic
al s
umm
ary
of n
utrie
nt c
once
ntra
tions
in w
ater
sam
ples
col
lect
ed a
t gag
ing
stat
ions
in th
e W
ither
s S
was
h B
asin
, M
yrtle
Bea
ch,
S.C
., S
epte
mbe
r 19
91 t
hrou
gh A
ugus
t t9
92--
Con
tinue
d
[All
conc
entra
tions
in m
illig
ram
s pe
r lit
er; <
, le
ss th
an; -
-, no
dat
a]
WAT
- S
TOR
E1
para
m
eter
co
de
7188
7
0066
5
70.5
07
0065
0
Con
stitu
ent
Nitr
ogen
,to
tal
Pho
spho
rus,
tota
lP
hosp
horu
s,or
tho,
tota
lP
hosp
hate
,to
tal
Sta
tion
021
1073
80
(Mai
nste
m B
ranc
h)
CD .a 5 Z 12 12 4 4
E
E X CO
15 1.3 .1
7
.52
E 1 'c 3
.19
.11
.34
c CO
T3 CD 2 4.7 .2
4
.14
.43
»_ E Z 12 12 5 5
Sta
tion
021
1073
85
(KO
A B
ranc
h)
E 1 X 231
1.7 .0
7
.20
E E c 3.3 .1
0
.05
.20
c .CO CD ^ 7.7 .3
0
.07
.20
CD .a | Z - 3 3 3
Sta
tion
02 11
073
88
(With
ers
Sw
ash)
E 1 X £ --
.09
.05
.15
E 1 'c --
.07
.04
,12
c .2 CD ^
--
.09
.08
.12
'Nat
iona
l Wat
er D
ata
Stor
age
and
Ret
riev
al S
yste
m o
f the
U.S
. G
eolo
gica
l Sur
vey.
Tabl
e 8.
--S
tatis
tical
sum
mar
y of
trac
e-el
emen
t con
cent
ratio
ns in
wat
er s
ampl
es c
olle
cted
at g
agin
g st
atio
ns in
the
With
ers
Sw
ash
Basi
n, M
yrtle
B
each
, S.
C.,
Sep
tem
ber
1991
thr
ough
Aug
ust
1992
[All
conc
entra
tions
in m
icro
gram
s pe
r lit
er; <
, le
ss th
an]
en
WA
T-
ST
OR
E1
para
m
eter
co
de
0109
7
0100
2
0101
2
0102
7
0103
4
0104
2
0072
0
0105
1
7190
0
Con
stitu
ent
Ant
imon
y,to
tal
Ars
enic
, tot
al
Ber
ylliu
m,
tota
l
Cad
miu
m,
tota
l
Chr
omiu
m,
tota
l
Cop
per,
tota
l
Cya
nide
,to
tal
Lead
, tot
al
Mer
cury
, tot
al
CD _Q E 3 z: 4 12 12 12 12 12 12 12 12
Sta
tion
02 11
073
80
(Mai
nste
m B
ranc
h)
* 1
g.ill
sis
l^
22
<1
1
6 <1
2
<10
<10
<10
2 <1
<1
27
<1
1
51
1 9.
5
<.01
<.
01
<.01
140
<1
9
.5
<1
.2
i_ CD .Q E 3 Z 5 12 12 12 12 12 11 12 12
Sta
tion
021
1073
85
(KO
A B
ranc
h)
S I
g^
3
(0.i
E
=6X
"£
Q
)
I H
s
2 <1
2
7 <1
3
<10
<10
<10
7 <1
.5
9 <1
1
62
3 23
.5
<.01
<.
01
<.01
450
4 10
9
.3
<.1
.1
L_ CD n 3 z. 3 3 3 3 3 3 3 3 3
Sta
tion
02 11
073
88
(With
ers
Sw
ash)
E
E
c
I
1
. 1
%
"c
JI
S
2
<1
<1
<1
322
<10
<10
<10
<10
<10
<10
4 <4
<4
<10
1 3
<.01
<.
01
<.01
<10
<10
<10
.2
.1 .1
Tabl
e 8.
-Sta
tistic
al s
umm
ary
of tr
ace-
elem
ent c
once
ntra
tions
in w
ater
sam
ples
col
lect
ed a
t gag
ing
stat
ions
in th
e W
ither
s S
was
h Ba
sin,
Myr
tle
Bea
ch,
S.C
., S
epte
mbe
r 19
91 t
hrou
gh A
ugus
t 79
92--
Con
tinue
d
[All
conc
entra
tions
in m
icro
gram
s pe
r lit
er; <
, le
ss th
an]
WAT
- S
TOR
E1
para
m
eter
code
0106
7
0114
7
0107
7
0109
2
Con
stitu
ent
Nic
kel,
tota
l
Sel
eniu
m,
tota
l
Silv
er, t
otal
Zinc
, tot
al
Sta
tion
021
1073
80
(Mai
nste
m B
ranc
h)
Number
12 12 12 12
Maximum
8 <2 <1 310
1 i
1 i
<1
1
<1
<1
<1
<1
10
60
Number
12 12 12 12
Sta
tion
021
1073
85
(KO
A B
ranc
h)
Maximum 65 <2 45
2,30
0
Minimum
1
<1 <1 20
Median
4.5
<1 3
145
Number 3 3 3 3
Sta
tion
021
1073
88
(With
ers
Sw
ash)
Maximum
1 <1 <1 30
1 *
1
I
<1
<1
<1
<1
<1
<1
<10
20
Nat
iona
l Wat
er S
tora
ge a
nd R
etri
eval
Sys
tem
of t
he U
.S. G
eolo
gica
l Sur
vey.
Values of pH were within State criteria for class SFH waters (pH between 6.0 and 8.5 standard pH units) for all but two samples. Two samples were collected at different times from the KOA Branch on July 20, 1992; pH values were 10.4 standard pH unit and 3.2 standard pH unit, whereas alkalinity concentrations for the same samples were 232 mg/L and le^s than 1.0 mg/L as CaCC>3, respectively. These data are suspect due to possible field and (or) laboratory contamination.
Specific conductance at the gaging stations on the Mainstem and KOA Branches ranged from 82 to 1,200 (iS/cm, whereas values in Withers Swash ranged from 36,600 to 45,200 uS/cm. The values at the downstream gaging station clearly show the influence of seawater carried into Withers Swash by the incoming tide.
Dissolved-oxygen concentrations ranged from 2.6 to 7.6 mg/L at the three gaging stations. Of the 27 samples collected, 6 of these were below the minimum concentration of 4.C mg/L suggested by the State criteria for class SFH waters, and concentrations in 12 other samples were below the required daily average of not less than 5.0 mg/L. Dissolved-oxygen concentrations at the gaging stations on the KOA Branch ranged from 2.6 to 5.3 mg/L. These concentrations are based on instantaneous measurements; more data would have to be collected to determine whether the daily mean concentration was greater than 5.0 mg/L. However, based on these data, the KOA Branch does not contain adequate dissolved-oxygen concentrations as suggested by State criteria for class SFH waters.
Water samples were examined for major ion concentrations including dissolved calcium, magnesium, sodium, potassium, chloride, and sulfate. Concentrations of these ion^ were detected at the gaging stations on the Mainstem and KOA Branches. Dissolved chloride concentrations ranged from 4.2 to 270 mg/L, with the highest value detected in the KOA Pranch. For other major ions detected in the water samples, the highest concentrations were detected in the KOA Branch. No comparisons were made to criteria, because major ions were not ir eluded in State criteria for class SFH waters or Human Health.
Nutrients were detected in almost every water sample collected at the three gaging stations. Results of analysis for 12 nutrients indicate that the highest concentrations of nutrients were detected at the gaging stations on the KOA Branch and concentrations were reduced in Withers Swash. No State criteria for nitrogen and phosphorus as nutrients were listed.
Water samples collected at the three gaging stations were examined for trace elements and cyanide. Trace elements were detected at all stations, but cyanide was not detected above the detection limit of 0.01 mg/L in the 26 samples collected. Also, concentrations of antimony, beryllium, and selenium were not detected or were near detection limits. The detection limit for beryllium of 10.0 (iig/L is much higher than the State Human Health criteria of 1.17 ug/L; therefore, it is not known if beryllium exceeds the State Human Health criteria. Thallium, asbestos, and 2, 3, 7, 8-TCDD (dioxin) were not examined in water samples collected in the Withers Swash Basin (table 9).
Arsenic, lead, cadmium, and mercury were detected at concentrations that violated State Human Health criteria (table 9). Arsenic concentrations ranged from below the detection limit of 1 to 7 |ig/L. The State Human Health criteria suggests a maximum arsenic concentration of 1.4 ng/L. Lead concentrations exceeded the State Human Health criteria of 5 ng/L in 6 of 12 samples collected from the KOA Branch and 2 of 12 samples collected from the Mcinstem Branch. The highest lead concentrations were in samples collected from the KOA Branch. Lead
17
Table 9.--Trace element, cyanide, asbestos, anddioxin compounds listed in the South Caro'!na Department of Health and Environmental Control Criteria for Protection of Human Health and the maximum concentrations detected within the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992
[SCDHEC, South Carolina Department of Health and Environmental Control; all valuesare in micrograms per liter unless otherwise noted; <, less than; --, no data;
TCDD, tetrachlorodibenzodioxin]
Constituents
Antimony
Arsenic
Beryllium
Cadmium
Chromium (III)
Chromium (VI)
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Cyanide
Asbestos
2,3,7,8-TCDD
Maximum allowable concentration in
SCDHEC Human Health criteria1
4,308
1.4
1.17
5
673,077
50
50
.153
4,584
10
50
48
200
27,000,000 f/L
3 1 2 ppq
Maximum concentration
detected in the Withers Swash
Basin
2
7
<10
7
--
--
450
.5
65
<2
45
--
<10
--
--
Values taken from Criteria for Protection of Human Health (South Carolina Department of Health and Environmental Control, 1993).
2Number of fibers per liter of water - based on consumption of water only. 3 Parts per quadrillion.
18
concentrations that exceeded State Human Health criteria ranged from 170 to 450 ug/L. Cadmium was detected in 6 of 12 samples collected from the KOA Branch. Two sample: contained cadmium concentrations of 7 ug/L. The State Human Health criteria suggests < maximum concentration of 5 ug/L. Cadmium also was detected in 1 of 12 samples collectec from the Mainstem Branch with a concentration of 2 ug/L. Cadmium was not detected in an) samples collected from Withers Swash. Mercury concentrations ranged from less than tru detection limit of 0.1 to 0.5 ug/L, and generally were higher in the Mainstem Branch than in the KOA Branch. Maximum contaminant concentration of mercury under State Human Health criteria is 0.153 ug/L.
The State Human Health criteria lists Chromium III, and Chromium VI, but these constituents were not examined in the Withers Swash Basin. The highest measured value for total chromium was 27 ug/L, which is below State Human Health criteria for Chromium III and Chromium VI of 673,077 ug/L and 50 ug/L, respectively.
The trace-element data indicate a pattern of higher concentrations of arsenic, crdmium, copper, lead, nickel, silver, and zinc in the KOA Branch than in the Mainstem Branch. Arsenic, cadmium, copper, and silver occur in various agricultural and household pesticides and also are used in the manufacturing of electronic devices (Lucius and others, 1992). Mercury is used in pharmaceutical and agricultural chemicals (Lucius and others, 1992).
Organic CompoundsThe water samples collected at the three gaging stations in the Withers Swash Ba^in were
examined for detectable concentrations of 61 volatile organic compounds, 55 acid- and base/neutral-extractable organic compounds, and 36 organic pesticide compounds (appendixes 4, 5, and 6). Results of analysis indicate that 12 compounds were detected in water from the Mainstem Branch, 19 in the KOA Branch, and 7 in Withers Swash (tables 10 and 11). The compounds, the number of water samples collected at each station, and the number of water samples in which compounds violate State Human Health criteria are listed in table 11.
The volatile organic compounds, 1,1,1-trichloroethane, 1,1-dichloroethane, 1,1-dichloroeth- ylene, l,2-dichloroethane,l,2-trans-dichloroethene, cis-l,2-dichloroethene, chlorobenzene, chlo- roethane, chloroform, ethylbenzene, methylenechloride, p-isopropyltoluene, toluene, trichloroethylene, vinyl chloride, and xylene were detected in samples collected from the KOA Branch, while 1,2-trans-dichloroethene, chloroform, cis-l,2-dichloroethene, and vinyl chloride were detected in samples collected from the Mainstem Branch (table 11). In samples collected from Withers Swash, 1,1,1-trichloroethane, 1,2-trans-dichloroethene, benzene, tetrachloroethyl- ene, and trichloroethylene were detected (table 11). Benzene and tetrachloroethylene were the only volatile organic compounds detected in Withers Swash that were not detected at e; ther the Mainstem or KOA Branches. All other volatile organic compounds were detected at much lower concentrations in Withers Swash than in the Mainstem and (or) the KOA Branches. The KOA Branch contained the largest number of and the highest concentrations of volatile organic com pounds of all water samples that were collected.
Some concentrations of 1,1-dichloroethylene, 1,1,1-trichloroethane, and trichloroethylene that were detected in water samples collected from the KOA Branch violated State Human Health criteria (table 12). In addition, the detection limit for acrylonitrile of 20.0 ug/L is higher than the State Human Health criteria of 6.65 ug/L; therefore, it is not known if acrylonitrile exceeds State Human Health criteria. The volatile organic compounds and highest allowable concentration listed in the State Human Health criteria along with the maximum concentrations detected in samples collected within the Withers Swash Basin are listed in table 12.
19
CO o
Tabl
e 10
.--S
tatis
tical
sum
mar
y of
vol
atile
org
anic
com
poun
ds,
acid
- and
bas
e/ne
utra
l-ext
ract
able
org
anic
com
poun
ds,
and
pest
icid
es in
wat
er
sam
ples
col
lect
ed a
t gag
ing
stat
ions
in th
e W
ither
s S
was
h Ba
sin,
Myr
tle B
each
, S.
C.,
Sep
tem
ber
1991
thr
ough
Aug
ust
1992
[iag/
L, m
icro
gram
s pe
r lit
er;
<, l
ess
than
; m
g/L,
mill
igra
ms
per
liter
; --,
no
data
; O
DD
, di
chlo
rodi
phen
yldi
chlo
roet
hane
; D
DE
, di
chlo
rodi
phen
yldi
chlo
roet
hyle
ne;
DO
T, d
ichl
orod
iphe
nyltr
ichl
oroe
than
e]
WA
T-
ST
OR
E1
code
3450
6
3449
6
3450
1
3403
0
3430
1
3431
1
3454
6
3210
3
Com
poun
ds
Uni
ts
1,1,
1-T
ri-
|ig/L
chlo
roet
hane
1,1-
Dic
hlor
o-
ng/L
etha
ne
1,1-
Dic
hlor
o-
ng/L
ethy
lene
Ben
zene
ja
g/L
Chl
oro-
|ig
/Lbe
nzen
e
Chl
oro-
|ig
/Let
hane
1 ,2-
tran
s-
jag/
LD
ichl
oro-
ethe
ne
1,2-
Dic
hlor
o-
jag/
Let
hane
Number 8 8 8 8 8 8 8 8
Sta
tion
021
1073
80
(Mai
nste
m B
ranc
h)
I !
S
'^
|
1
<0.
2 <
0.2
<2
<2
<2
<
2
<2
<
2
<2
<
2
<2
<
2
.8
<2
<2
<
2
c o5
&
n
o
E
i I
Vol
atile
org
anic
0.2
8
<.2
8
<.2
8
<.2
8
<.2
8
<.2
8
<.2
8
<.2
8
Sta
tion
021
1073
85
(KO
A B
ranc
h)
I 1
1
com
poun
ds
350
27
87.5
4.3
1.2
2.8
26
.6
2.5
<2
<
2
<2
2
<2
<
2
,6
<.2
.4
13
<.2
3.
8
.4
<.2
<.
2
Number 3 3 3 3 3 3 3 3
Sta
tion
021
1073
88
(With
ers
Sw
ash)
| |
|X
"F
0)
j
5
0.6
<0.
2 0.
2
^f f)
jf f\
^f rt
^
O
^ O
***
O
.6
<.2
<2
<2
<
2
<2
<2
<
2
<2
2 1
1.9
<.2
<2
<2
Tabl
e 10
.--S
tatis
tical
sum
mar
y of
vol
atile
org
anic
com
poun
ds,
acid
- and
bas
e/ne
utra
l-ext
ract
able
org
anic
com
poun
ds,
and
pest
icid
es in
wat
er
sam
ples
col
lect
ed a
t gag
ing
stat
ions
in t
he W
ither
s S
was
h B
asin
, M
yrtle
Bea
ch,
S.C
., S
epte
mbe
r 19
91 t
hrou
gh A
ugus
t 79
92--
Con
tinue
d
[[ig/
L, m
icro
gram
s pe
r lit
er;
<, le
ss th
an;
mg/
L, m
illig
ram
s pe
r lit
er; -
-, no
dat
a; O
DD
, dic
hlor
odip
heny
ldic
hlor
oeth
ane;
D
DE,
dic
hlor
odip
heny
ldic
hlor
oeth
ylen
e; D
OT,
dic
hlor
odip
heny
ltric
hlor
oeth
ane]
WA
T-
ST
OR
E1
code
Com
poun
ds
Uni
ts
Number
Sta
tion
021
1073
80
(Mai
nste
m B
ranc
h)
1 1
* *
.E
E
-o
E
%
c
^
§3
ii ^
z
Sta
tion
021
1073
85
(KO
A B
ranc
h)
1 I
«.E
E
TO
X
"c
CD
CO
^=
^
s ^
^
Sta
tion
021
1073
88
(With
ers
Sw
ash)
& 1
| fill
§
X
"c
CD
Vol
atile
org
anic
com
poun
ds-C
ontin
ued
3210
6
7735
6
7709
3
3437
1
3442
3
3447
5
3401
0
3918
0
3917
5
8155
1
Chl
orof
orm
[ig
/L
p-ls
opro
pyl-
[ig/L
to
luen
e
cis-
1 ,2
-Di-
[ig/L
chlo
roet
hene
Eth
ylbe
n-
[ig/L
zene
Met
hyle
ne
(ig/L
ch
lorid
e
Tetra
chlo
ro-
[ig/L
ethy
lene
Tolu
ene
[ig/L
Tric
hlor
o-
[ig/L
ethy
lene
Vin
vl c
hlor
ide
ug/L
Xyl
ene
[ig/L
8 4 4 8 8 8 8 8 8 8
0.3
<0.2
<0
.2
8
<.2
<.2
<.2
3
.9
<.2
.85
3
<.2
<.2
<.2
8
<.2
<.2
<.2
8
<.2
<.2
<.2
8
<.2
<.2
<.2
8
<.2
<.2
<.2
8
0.2
<0.2
<0
.2
8
<.2
<.2
<.2
8
1 <0
.2
0.6
.3
<.2
<.2
14
4.7
5.8
.2
<.2
<.2
.8
<.2
<.2
<.2
<.2
<.2
.9
<.2
.3
48
5.2
9.4
1.2
<0.9
0.
3
.5
<.2
<.2
3 <0
.2
<0.2
<0
.2
-- 3 <.
2 <.
2 <.
2
3 <.
2 <.
2 <.
2
3 .3
.2
.2
3 <.
2 <.
2 <.
2
3 2.
6 1.
2 <.
4
3 <0
.2
<0.2
<0
.2
3 <.
2 <.
2 <.
2
N)
Tabl
e 10
.--S
tatis
tical
sum
mar
y of
vol
atile
org
anic
com
poun
ds, a
cid-
and
bas
e/ne
utra
l-ext
ract
able
org
anic
com
poun
ds,
and
pest
icid
es in
wat
er
sam
ples
col
lect
ed a
t gag
ing
stat
ions
in th
e W
ither
s S
was
h Ba
sin,
Myr
tle B
each
, S.
C.,
Sep
tem
ber
1991
thr
ough
Aug
ust
7992
--C
ontin
ued
, mic
rogr
ams
per
liter
; <,
less
than
; m
g/L,
mill
igra
ms
per
liter
; --,
no d
ata;
DD
D, d
ichl
orod
iphe
nyld
ichl
oroe
than
e;
DD
E, d
ichl
orod
iphe
nyld
ichl
oroe
thyl
ene;
DDT
, dic
hlor
odip
heny
ltric
hlor
oeth
ane]
WA
T-
ST
OR
E1
code
Com
poun
ds
Uni
ts
Number
Sta
tion
021
1073
80
(Mai
nste
m B
ranc
h)
I 1
Median
Number
Sta
tion
021
1073
85
(KO
A B
ranc
h)
i 1
§.E
E
=o
%
'c
®£
l 2
Sta
tion
021
1073
88
(With
ers
Sw
ash)
* i
! s
I -1
I "s
Acid
- an
d ba
se/n
eutra
l-ext
ract
able
org
anic
com
poun
ds
0055
6
3437
6
3273
0
3935
0
3936
0
3936
5
3937
0
3938
0
Oil
and
mg/
Lgr
ease
Fluo
rant
hene
jig
/L
Phe
nols
, jig
/Lto
tal
Chl
orda
ne
jig/L
DD
D
jig/L
DD
E
[ig/L
DD
T jig
/L
Die
ldrin
[ig
/L
8 4 4 7 4 4 4 7
3 <1
7 <5
3 1
.3
<.1
.03
<.01
.02
<.01
.03
<.01
.01
<.02
<1 <5 2.5
Org
anic
<-1 .0
1
.01
<.01 .0
1
8 5 5
pest
icid
e
7 5 5 5 7
2 <1
1
5 <5
<5
3 1
3
com
poun
ds
<.1
<.1
<.1
<.01
<.
01
<.01
<.01
<.
01
<.01
<.01
<.
01
<.01
<.02
<.
01
<.01
3 1
<1
1
3 <5
<5
<5
3111
3 <.
1 <.
1 <.
1
3 <.
01
<.01
<.
01
3 <.
01
<.01
<.
01
3 <.
01
<.01
<.
01
3 <.
01
<.01
<.
01
'Nat
iona
l Wat
er S
tora
ge a
nd R
etrie
val S
yste
m o
f the
U.S
. Geo
logi
cal S
urve
y.
Table 11 .-Summary of organic compounds detected in water samples collected at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., and number of water samples in which concentrations exceed the South Carolina Department of Health and Environmental Control Human Health criteria, September 1991 through August 1992
[SCDHEC, South Carolina Department of Health and Environmental Control; --, no data;ODD, dichlorodiphenyldichloroethane; DDE, dichlorodiphenyldichloroethylene;
DOT, dichlorodiphenyltrichloroethane]
Compound
Number of Number of water water samples
samples in which collected compounds
were detected
Number of water samples in wh'oh
concentration^exceed the SCDHEC
Human Health criteria
Station 021107380 (Mainstem Branch)
1 ,2-trans-Dichloroethene
Chlordane
Chloroform
cis-1 ,2-Dichloroethene
ODD
DDE
DOT
Dieldrin
Fluoranthene
Oil and grease
Phenols
Vinyl chloride
8
7
8
4
4
4
4
7
4
8
4
8
2
3
3
3
2
2
1
2
1
4
4
3
0
3
0
--'
-- 1
--'
--'
2
0
-J
0
0
Station 021107385 (KOA Branch)
1,1,1-Trichloroethane
1,1-Dichloroethane
1,1-Dichloroethylene
1 ,2-Dichloroethane
1 ,2-trans-Dichloroethene
cis-1 ,2-Dichloroethene
Chlorobenzene
Chloroethane
8
8
8
8
8
3
8
8
8
8
8
1
5
3
2
7
2
--'
1
0
0
--'0
-J
23
Table 11 .--Summary of organic compounds detected in water samples collected at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., and number of water samples in which concentrations exceed the South Carolina Department of Health and Environmental Control Human Health criteria, September 1991 through August 7992~Continued
[SCDHEC, South Carolina Department of Health and Environmental Control; --, no data;ODD, dichlorodiphenyldichloroethane; DDE, dichlorodiphenyldichloroethylene;
DOT, dichlorodiphenyltrichloroethane]
CompoundNumber of water
samples collected
Number of water samples
in which compounds
were detected
Number of water samples in which concentrations
exceed the SCDHEC Human Health
criteria
Station 021107385 (KOA Branch)-Continued
Chloroform
Ethylbenzene
Fluoranthene
Methylene chloride
Oil and grease
Phenols
p-lsopropyltoluene
Toluene
Trichloroethylene
Vinyl chloride
Xylene
1,1,1 -Trichloroethane
1 ,2-trans-Dichloroethene
Benzene
Oil and grease
Phenols
Tetrachloroethylene
Trichloroethylene
8
8
5
8
8
5
3
8
8
8
8
Station 021107388 (Withers
3
3
3
3
3
3
3
7
1
1
3
6
5
1
6
8
6
3
Swash)
2
3
1
2
3
3
3
0
0
0
0
--'
0
--'
0
8
0
-J
0
0
0
-- 10
0
0
Compound not listed in SCDHEC Human Health criteria.
24
Table 12. --Volatile organic compounds listed in the South Carolina Department of Health and Environmental Control Criteria for Protection of Human Health and the maximum concentrations detected within the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992
[SCDHEC, South Carolina Department of Health and Environmental Control; all values are in micrograms per liter unless otherwise noted; <, less than]
Constituents
Acrolein
Acrylonitrile
Benzene
Bromoform
Carbon tetrachloride
Chlorobenzene
Chlorodibromomethane
2-Chloroethylvinyl ether
Chloroform
Dichlorobromomethane
1 ,2-Dichloroethane
1,1-Dichloroethylene
1 ,3-Dichloropropylene (cis & trans)
Ethylbenzene
Methyl bromide
Methyl chloride
Methylene chloride
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1 ,2-trans-Dichloroethene
1,1,1-Trichloroethane
Maximum allowable
concentration in SCDHEC Human
Health criteria1
780
6.65
5
100
5
488
100
176
100
100
5
7
1,691
28,718
4,708
4,708
15,780
108
88.5
1,000
136,319
200
Maximum concentration detected in the Withers Swash
Basin
<20
<20
.6
<.2
<.2
.2
<.2
<1
1
<.2
.4
26
<.2
.2
<.2
<.2
.8
<.2
.3
.9
13
350
25
Table 12.-- Volatile organic compounds listed in the South Carolina Department of Health and Environmental Control Criteria for Protection of Human Health and the maximum concentrations detected within the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 7992--Continued
[SCDHEC, South Carolina Department of Health and Environmental Control; all values are in micrograms per liter unless otherwise noted; <, less than]
Constituents
1 ,1 ,2-Trichloroethane
Trichloroethylene
Vinyl chloride
Maximum allowable
concentration in SCDHEC Human
Health criteria 1
419.9
5
2
Maximum concentration
detected in the Withers Swash
Basin
<.2
48
1.2
'Values taken from Criteria for Protection of Human Health (South Carolina Department of Health and Environmental Control, 1993).
The volatile organic compounds detected in the highest concentrations are members of a family of organic compounds that are commonly used as degreasers and as solvents ti remove fats, waxes, resins, oil, rubber, paint, and varnishes. Specifically, trichloroethylene is used as a metal degreaser. In the environment, trichloroethylene can be transformed abiotically and biotically to compounds containing fewer chlorine atoms, such as dichloroethylene and vinyl chloride. Trichloroethylene can be transformed to its degradation products through photocatalytic dechlorination in surface-water systems (Ollis, 1985), but is more commonly dechlorinated by a community of anaerobic bacteria in shallow ground-water systems (Wood and others, 1985). The extent of the contamination in the vicinity of the sampling sites is not known, because sampling of ground water was not included within the scope of this study The presence of dichloroethylene and vinyl chloride in the KOA Branch during periods where streamflow was at base-flow conditions (ground-water discharge into the stream) raises the possibility that a substantial source of these products exists in the subsurface and is affecting the water quality of surface waters.
Results of analyses for acid- and base/neutral-extractable organic compounds indicated that only oil and grease, total phenols, and fluoranthene were detected. Concentrations of oil and grease ranged from less than the detection limit of 1 to 3 mg/L. Oil and grease is not listed in the State Human Health criteria. The highest concentration of fluoranthene detected (7.0 ug/L) is less than the State Human Health criteria of 370 ug/L; the highest concentration of total phenol (3 ng/L) is less than the State Human Health criteria of 3,500 |^g/L (tables 13 and 14). Ten base/neutral-extractable organic compounds (benzidine, benzo(a)arithracene, benzo(a)pyrene, 3,4-benzofluoranthene, benzo(k)fluoranthene, chrysene, dibenz(a,h)anthracene, hexachlorobenzene, indeno(l,2,3-cd)pyrene, and phenanthrene) were all below detection limits, but detection limits were higher than State Human Health criteria. It is not known if tl^se com pounds exceed State Human Health criteria. The highest allowable concentrations- of acid- base/neutral-extractable organic compounds listed in the State Human Health criteria along with the maximum concentrations detected in samples collected within the Withers Swash Basin are listed tables 13 and 14.
26
Table 1 3.-Add-extractable organic compounds listed in the South Carolina Department of Health and Environmental Control Criteria for Protection of Human Health and the maximum concentrations detected within the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992
[SCDHEC, South Carolina Department of Health and Environmental Control; all values are in micrograms per liter unless otherwise noted; <, less than; --, no data]
Compounds
2,4-Dichlorophenol
2-Methyl-4,6 dinitrophenol
2,4-Dinitrophenol
Pentachlorophenol
Phenol
2,4,6-Trichlorophenol
Maximum allowable
concentration in SCDHEC Human
Health criteria1
3,090
765
14,264
81.6
3,500
36
Maximum concentration detected in tho Withers Swash
Basin
<5
--
<20
<30
3
<20
Values taken from Criteria for Protection of Human Health (South Carolina Department of Health and Environmental Control, 1993).
Results of analyses for 36 selected organic pesticides and non-specific polychlorinated naphthalenes indicated that most concentrations were below detection limits in the KOA Branch and Withers Swash (tables 10, 11, and 15; appendix 6). However, total DDD, DDE, and DDT were detected in some samples collected at the Mainstem Branch; concentrations ranged below the detection limit of 0.01 to 0.03 ng/L. Dieldrin was detected in some samples at concentrations equal to the detection limit of 0.01 ng/L and chlordane at concentrations ranging from less than detection limit of 0.1 to 0.3 ng/L. Dieldrin and chlordane were only detected at tH gaging station on the Mainstem Branch. The pesticides DDD, DDE, and DDT were not included in State Human Health criteria, but dieldrin and chlordane violated State Human Health criteria of 0.00144 jig/L and 0.00588 jig/L, respectively Although chlordane and DDT are ro longer produced within the United States, these pesticides and the by-products of DDT (DDD and DDE) are persistent. There were no detections of polychlorinated naphthalenes in any of the samples. The detection limits for aldrin, p-p'-DDT, heptachlor, heptachlor epoxide, the PCB's and toxaphene were all greater than the State Human Health criteria; therefore, it is not known if these pesticide and PCB compounds exceed State Human Health criteria. The maximum allowable concentrations of pesticide and PCB compounds listed in the State Human Health criteria along with the maximum concentrations detected in samples collected within the Withers Swash Basin are listed in table 15.
27
Table '\4.--Base/neutral-extractable organic compounds listed in the South CarolinaDepartment of Health and Environmental Control Criteria for Protection of Human Health and the maximum concentrations detected within the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992
[SCDHEC, South Carolina Department of Health and Environmental Control; all values are in micrograms per liter unless otherwise noted; <, less than; --, no data]
Compounds
Anthracene
Benzidine
Benzo(a)anthracene
Benzo(a) pyrene
3,4-Benzofluoranthene
Benzo(k)fluoranthene
Bis(2-chloroethyl) ether
Bis(2-chloroisopropyl)ether
Bis(2-ethylhexyl)phthalate
Butylbenzylphthalate
Chrysene
Dibenz(a,h)anthracene
1 ,2-Dichlorobenzene
1 ,3-Dichlorobenzene
1 ,4-Dichlorobenzene
3,3 '-Dichlorobenzidine
Diethyl phthalate
Dimethyl phthalate
Di-n-butyl phthalate
2,4-Dinitrotoluene
1 ,2-Diphenylhydrazine
Fluoranthene
Fluorene
Maximum allowable
concentration in SCDHEC Human
Health criteria1
110,000
.00535
.311
.311
.311
.311
14.2
174,400
59.2
5,202
.311
.311
17,432
2,600
75
.77
118,019
2,900,000
12,100
91
5.4
370
14,000
Maximum concentration detected in the Withers Swash
Basin
<5
<40
<10
<10
<10
<10
<5
<5
<5
<5
<10
<10
--
--
--
--
<5
<5
<5
<5
<5
7
<5
28
Table 14.~Base/neutral-extractable organic compounds listed in the South CarolinaDepartment of Health and Environmental Control Criteria for Protection of Human Health and the maximum concentrations detected within the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August f992--Continued
[SCDHEC, South Carolina Department of Health and Environmental Control; all values are in micrograms per liter unless otherwise noted; <, less than; --, no data]
Compounds
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclopentadiene
Hexachloroethane
lndeno(1 ,2,3-cd)pyrene
Isophorone
Nitrobenzene
N-Nitrosodimethylamine
N-Nitrosodiphenylamine
Phenanthrene
Pyrene
Maximum allowable
concentration in SCDHEC Human
Health criteria1
0.0077
497
206
88.5
.311
6,000
1,863
81.2
162
.311
11,000
Maximum concentration detected in the Withers Swash
Basin
<5
<5
<5
<5
<10
<5
<5
<5
<5
<5
<5
'Values taken from Criteria for Protection of Human Health (South Carolina Department of Health and Environmental Control, 1993).
A screening technique for the determination of organic substances in water was used on 24 water samples during late 1991 and 1992 (table 16). The gas chromatograph/flame ionization detector (GC/FID) analysis or FID scan provided semi-quantitative data that were used to determine presence and magnitude of organic substances. The technique does not identify specific organic compounds. However, FID scans from samples showing high concentrations of non-specific organic compounds were further analyzed to identify the specific organic compounds.
29
Table 15.--Pesticide and PCB compounds listed in the South Carolina Department of Health and Environmental Control Criteria for Protection of Human Health and the maximum concentrations detected within the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992
[SCDHEC, South Carolina Department of Health and Environmental Control;all values are in micrograms per liter unless otherwise noted; <, less than;
BHC, benzene hexachloride; DOT, dichlorodiphenyltrichlorethane;PCB, polychlorinated biphenyls]
Compounds
Aldrin
alpha-BHC
beta-BHC
delta-BHC
Chlordane
p-p'-DDT
Dieldrin
alpha-Endosulfan
beta-Endosulfan
Endrin
Heptachlor
Heptachlor epoxide
PCB-1242
PCB-1254
PCB-1221
PCB-1232
PCB-1248
PCB-1260
PCB-1016
Toxaphene
Maximum allowable
concentration in SCDHEC Human
Health criteria1
0.0136
.131
.46
.625
.00588
.0059
.00144
1.99
1.99
.2
.00214
.001
.00045
.00045
.00045
.00045
.00045
.00045
.00045
.0075
Maximum concentration
detected in the Withers Swash
Basin
<0.04
<.03
<.03
<.09
.3
<.1
.01
<.1
<.04
<.06
<.03
<.8
<.1
<.1
<1
<.1
<.1
<.1
<.1
<2
Values taken from Criteria for Protection of Human Health (South Carolina Department of Health and Environmental Control, 1993).
30
Table 1 6. --Results of gas chromatograph/flame ionization detector (GC/FID) analyses of water samples collected in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992
, cubic feet per second; ng/L, micrograms per liter; ND, none detected; --, no data]
Station number (identifier)
(fig- 2)
021107380 (Mainstem Branch)
021107385(KOA Branch)
021107388(Withers Swash)
Date
09-20-91 09-24-9109-24-9109-24-91
07-18-9207-20-9207-20-9207-20-92
08-03-9208-03-9208-03-92
09-20-9109-24-9109-24-9109-24-9109-24-91
07-18-9207-20-9207-20-92
08-03-9208-03-92
09-24-9109-24-9109-24-91
Time (hours)
0300 133016351655
1845172017251745
141215382100
03051330164017151805
183018051840
14301610
131521042154
Instantaneous flow
(ft3/s)
1.1 .60
1711
.601.31.82.4
1065
6.2
2.11.55.25.33.2
1.62.12.5
1771
----
Concentration of non-specific
organic compounds
detected
25 ND50
9
177
1663
1201976
30ND
1,000450
9
382562159
26326
NDNDND
31
Nine of the 24 samples were analyzed for identification of specific organic compounds. In these 9 samples, 42 organic compounds were identified: four organic compounds were identified by type of compound only (table 17). The four unidentifiable organic compounds were classified as an alkane, an alkene, an organic acid, and an unknown compound. Three organic compounds were identified at concentrations higher than 40 ug/L in water samples collected from the KOA Branch. These were an ester of bis(l-methylpropyl) carbonic acid, 2-butoxyethanol (butylcellosolve), and alpha-terpineol. These compounds can be attributed to a variety of sources. The concentrations of alpha-terpineol can come from natural oils from pine forests (Verschueren, 1983). Butylcellosolve is used as a solvent for nitrocellulose, resins, grease, oil and albumin, and in the dry cleaning process (Stecher and others, 1960). The esters of carbonic acid are used in numerous manufacturing processes.
Analysis of the data indicates that the majority of detections and the highest concentrations of organic compounds were in water samples collected from the KOA Branch. Unidentifiable organic compounds also were detected at concentrations of 200 ug/L and 300 ug/L in two water samples collected from the KOA Branch.
Enteric BacteriaFecal coliform and fecal streptococcus bacteria are enteric bacteria indigenous to the
intestines of humans and other warm-blooded animals. Fecal coliform bacteria are considered a reliable indicator of fecal contamination in streams, and can multiply in water under some environmental conditions. Fecal streptococcus bacteria do not multiply in water; therefore, the presence of fecal streptococcus bacteria in water indicates fecal pollution with a density equal to or less than that originally present (Clark and others, 1977). The presence of either of these indicator bacteria reflects the potential for contamination by pathogenic enteric microorganisms.
In every water sample collected from the three gaging stations during a storm, enteric- bacteria concentrations increased as streamflow began to increase (tables 18 and 19). The Mainstem and KOA Branches exhibited an initial increase of enteric-bacteria counts that can be attributed to the initial washoff of pollutants from impervious surfaces. However, enteric- bacteria counts within the Withers Swash Basin were not depleted after the initial washoff of pollutants, but continued to rise throughout the storm.
A possible explanation to high bacteria counts at peak streamflow may be thit as streamflow increased, the high velocities created turbid conditions, suspending small sediment particles. Fecal coliform are present as discrete cells, and as part of large aggregates of fecal materials, storm-water debris and other suspended solids (Schillinger and Gannon, 1982). Auer and Niehaus (1993) observed that on the average, 90.5 percent of fecal coliform bacteria were associated with sediment particles ranging in size from 0.45 to 10 jim, and 9.5 percent were associated with sediment particles greater than 10 jim in size. The smaller particles arrive at the sampling station during the high streamflow period where velocities are at maximum values.
In some cases, enteric-bacteria counts increased as streamflow was receding. For exa mple, on September 24, 1991, as streamflow increased on the Mainstem Branch from 0.6 to 17 fr/s, fecal coliform counts increased from 3,800 to 92,000 col/100 mL; but as the streamflow receded to 11 ftVs, the counts continued to increase to 1,500,000 col/100 mL (table 18). Fecal coHfonn bacteria attached to larger streambed sediments are rolled along the streambed by rapid, turbulent streamflow, and arrive at the downstream point as streamflow is receding (McC onald and Kay, 1981; McDonald and others, 1982; Kay and McDonald, 1983). However, the enteric bacteria adsorbed onto large particles alone do not account for the high enteric-bacteria counts.
32
Tabl
e 17
.-R
esul
ts o
f Nat
iona
l Ins
titut
e of
Sta
ndar
ds a
nd T
echn
olog
y lib
rary
sea
rch
of c
hrom
atog
ram
s fro
m g
as c
hrom
atog
raph
/flam
e io
niza
tion
dete
ctor
ana
lyse
s of
wat
er s
ampl
es c
olle
cted
from
the
With
ers
Sw
ash
Basi
n, M
yrtle
Bea
ch,
S.C
., S
epte
mbe
r 19
91
[All
conc
entra
tions
in m
icro
gram
s pe
r lit
er;
(),
date
; [ ]
, tim
e, h
our;
--, n
o da
ta;
<, l
ess
than
]
GO
GO
Sta
tion
021
1073
80
Con
stitu
ent
Alk
ane
Alk
ene
Ace
naph
then
eA
nthr
acen
eA
nthr
acen
e
9,1
0-A
nthr
acen
edio
neA
trazi
neB
enza
ldeh
yde,
4-h
ydro
xy-3
-met
hoxy
1 ,2-
Ben
zene
dica
rbox
ylic
aci
dB
enzo
(a)
ant
hrac
ene
Ben
zo (
b) fl
uora
nthe
neB
enzo
(k)
fluo
rant
hene
Ben
zoic
aci
dB
enzo
(g,
h,i)
pery
lene
Ben
zo (
a) p
yren
e
Ben
zo (
h) q
uino
line
2 (3
H)-
Ben
zoth
iazo
lone
Bis
(2-e
thyl
hexy
l)pht
hala
teC
affe
ine
9H-C
arba
zole
Car
boni
c ac
id,
bis(
l-met
hylp
ropy
l) es
ter
Chr
ysen
eD
ecan
oic
acid
(9-2
0-91
) (9
-24-
91)
[030
0]
[163
5]
10
<1 <1- <1
3
<1
<11 2 1
16 3
<1 <13
3 <1
1
_. <1
4<1
(9-2
4-91
) [1
655] 4 ~ <1
2 ~ - 1 1 1 ~ 4 2 - - - ~ 2 3
Sta
tion
021
1073
85
(9-2
0-91
) (9
-24-
91)
[030
5]
[164
0]
102
1-
<1--
2_.
1-
1 2 2..
5 2
<1-- ..
<1 100 2
(9-2
4-91
) (9
-24-
91)
[171
5]
[180
5]
2 <1
- ._ <1
1 1 2
<12
<1
1 1
1 1
2 4 2 __ -- ~ 1 1
._
100 2
1
Sta
tion
021
1073
88
(9-2
4-91
) (9
-24-
91)
[210
4]
[215
4]
.. - - __ ._ .. -- - .. ~ -- ._ - _. ._ - ._ <1
4<1
Tabl
e 17
.--R
esul
ts o
f Nat
iona
l Ins
titut
e of
Sta
ndar
ds a
nd T
echn
olog
y lib
rary
sea
rch
of c
hrom
atog
ram
s fro
m g
as c
hrom
atog
raph
/flam
e io
niza
tion
dete
ctor
ana
lyse
s of
wat
er s
ampl
es c
olle
cted
from
the
With
ers
Sw
ash
Bas
in,
Myr
tle B
each
, S.
C.,
Sep
tem
ber
799/
--C
ontin
ued
[All
conc
entra
tions
in m
icro
gram
s pe
r lit
er;
(),
date
; [ ]
, tim
e, h
our;
--, n
o da
ta;
<, l
ess
than
]
00
Sta
tion
021
1073
80
Con
stitu
ent
Eth
anol
, 2-
buto
xyE
than
ol,2
-[2-(
2-bu
toxy
etho
xy)e
thox
y]-
Eth
anol
, 2-
buto
xy-,
phos
phat
e (3
:1)
Fluo
rant
hene
Fluo
rene
Hex
adec
anoi
c ac
idIn
deno
(1 ,2
,3-c
d)py
rene
1 ,3-
lsob
enzo
fura
ndio
ne1 (
SH
)-ls
oben
zofu
rano
neIs
oter
pino
lene
Org
anic
aci
dP
hena
nthr
ene
(9-2
0-91
) [0
300] ~ 9 1 ~ __ ~ ~ 1 -- 9
<1
(9-2
4-91
) [1
635] -- ~ 7
<1 20 6 ~ <22
(9-2
4-91
) [1
655] ~ ~ ~ 5 - __ 5 - - ~ 1
Sta
tion
021
1073
85
(9-2
0-91
) (9
-24-
91)
[030
5]
[164
0]
600 3 9
<1
5~
8 5<1
~
2
1<1
(9-2
4-91
) [1
715] ~ 10 3 -- 4 5 ~ ~ ~ <1
(9-2
4-91
) [1
805] ~ - 4 1 ~ ._ -- ~ ~ 1
<1
Sta
tion
021
1073
88
(9-2
4-91
) (9
-24-
91)
[210
4]
[215
4]
- - <1
<1.. - - __
Phe
nol,
3-(1
,1-d
imet
hyle
thyl
)-
Phe
nol,
4-(1
-met
hylp
ropy
l)-
Phe
nol,
nony
l-
Pro
pano
ic a
cid,
2,2
-dim
ethy
l-P
yren
eP
yren
e, 1
-met
hyl-
Sulfu
r, m
ol.
(S8)
alph
a-Te
rpin
eol
cis-
beta
-Ter
pine
olTe
trade
cano
ic a
cid
Unk
now
n
5<1
5
3 -.4
-
5 <1
--8
40
._
520
0
__ 2 1
1 4 -- 1 ._
300
- <1
<1__ _. -- __ --
Tabl
e 18
.-S
umm
ary
of s
ampl
ing
cond
ition
s an
d en
teric
-bac
teria
cou
nts
for s
tatio
n 02
1107
380,
Mai
nste
m B
ranc
h of
With
ers
Sw
ash,
Myr
tle B
each
, S.
C.,
Aug
ust
1991
thr
ough
Jun
e 19
93
[ft3/
s, c
ubic
feet
per
sec
ond;
col
/100
mL,
col
onie
s pe
r 10
0 m
illili
ters
; --,
no
data
]
Sam
plin
g da
te
08/0
1/91
09/1
0/91
09/1
9/91
09/2
0/91
09/2
4/91
06/0
4/92
06/1
5/92
07/1
8/92
07/1
9/92
07/2
0/92
Wea
ther
co
nditi
on
dry
dry
wet
wet
wet
wet
dry
dry
wet
wet
Num
ber
of d
ry
Rai
nfal
l da
ys p
rior
to
amou
nt
rain
fall
(inch
es)
0 0 17
0.05
0 .0
7
0 .4
2
4 .4
6
0 20 21
.05
0 .1
6
Stre
amflo
w
(ft3/
s)
0.78 -- .6
0
1.1
1.6
1.2 .6
0
17 11 9.1
7.2 .6
0
.85
1.3
1.8
14
1.5
Tim
e (h
ours
)
-- --
1310
0300
0330
0700
1330
1635
1655 -- --
1845
1430
1720
1725
1745
1835
Feca
l col
iform
(c
ol/1
00
mL)
2,50
0
-- 1,40
0
220,
000
640,
000
800,
000
3,80
0
92,0
00
1 ,50
0,00
0
10,0
00
2,70
0
6,00
0
59,0
00
15,3
00
'5,0
00
'34,
000,
000
'27,
000,
000
Feca
l st
rept
ococ
cus
(col
/1 0
0 m
l)
1,30
0
1,80
0
'100
'600
4,40
0
'550
2,40
0
71 ,0
00
165,
000
--
3,50
0
'14,
000
15,0
00 300
300
380,
000
'190
,000
Tabl
e 18
.~S
umm
ary
of s
ampl
ing
cond
ition
s an
d en
teric
-bac
teria
cou
nts
for s
tatio
n 02
1107
380,
Mai
nste
m B
ranc
h of
With
ers
Sw
ash,
Myr
tle B
each
, S
.C.,
Aug
ust
1991
thr
ough
Jun
e 79
93--
Con
tinue
d
[ft3/
s, c
ubic
feet
per
sec
ond;
col
/100
ml,
colo
nies
per
100
mill
ilite
rs;
--, n
o da
ta]
GO O
Sam
plin
g da
te
08/0
3/92
08/0
4/92
08/0
5/92
06/2
2/93
Wea
ther
co
nditi
on
wet dry
dry
dry
Num
ber
of d
ry
Rai
nfal
l da
ys p
rior t
o am
ount
ra
infa
ll (in
ches
)
7 2.
68
0 1
2..
Stre
amflo
w
(ft3/
s)
10 65 6.2
7.9
2.8 -- --
Tim
e (h
ours
)
1412
1535
2100 -- -- -- --
Feca
l col
iform
(c
ol/1
00
ml)
55,0
00
38,0
00
31,0
00
13,0
00
2,00
0 32 30
Fec
al
stre
ptoc
occu
s (c
ol/1
00
ml)
88,0
00
58,0
00
35,0
00
56,0
00
1,40
0 36 30
Non
-ide
al c
ount
.2N
umbe
r of
dry
day
s an
d st
ream
flow
wer
e no
t det
erm
ined
bec
ause
gag
es w
ere
rem
oved
.
Tabl
e 19
.--S
umm
ary
of s
ampl
ing
cond
ition
s an
d en
teric
-bac
teria
cou
nts
for s
tatio
n 02
1107
385,
KO
A B
ranc
h of
With
ers
Swas
h, M
yrtle
Bea
ch,
S.C
. A
ugus
t 19
91 t
hrou
gh J
une
1993
[ft3/
s, c
ubic
feet
per
sec
ond;
col
/100
mL,
col
onie
s pe
r 10
0 m
illili
ters
; --,
no d
ata;
<,
less
than
; >, g
reat
er th
an]
CJ
Sam
plin
g da
te
08/0
1/91
09/1
0/91
09/1
9/91
09/2
0/91
09/2
4/91
11/0
8/91
06/0
4/92
07/1
8/92
07/1
9/92
Wea
ther
co
nditi
on
wet dry
dry
wet
wet dry
wet
dry
dry
Num
ber o
f dry
a
days
prio
r to
rain
fall
v '
0 0.
56
8 17 18
.08
0 .3
5
23 4 .9
2
15 1fi
Stre
amflo
w
(ft3/
s)
1.4
1.6
1.6
2.1
2.3
1.7
1.5
5.2
5.3
3.2
1.9
4.0
1.6
1.6
Tim
e (h
ours
)
- ~ --
1315
0305
0345
0700
1330
1640
1715
1805 -- --
1830
1445
Feca
l co
lifor
m
(col
/1 0
0 m
l)
3,90
0
3,00
0
-
1,20
0
21,0
00
19,0
00
12,0
00
1,90
0
45,0
00
100,
000
27,0
00
1,60
0
2,80
0
5,50
0
5,00
0
Fec
al
stre
ptoc
occu
s (c
ol/1
00
ml)
<20
<20
^,3
00
<50
<50
'50
<50
2,40
0
37,0
00
50,0
00
28,0
00
1,00
0
-
>1 0
,000
13,0
00
Tabl
e 1 ^
.--S
umm
ary
of s
ampl
ing
cond
ition
s an
d en
teric
-bac
teria
cou
nts
for s
tatio
n 02
1107
385,
KO
A B
ranc
h of
With
ers
Swas
h, M
yrtle
Bea
ch,
S.C
., A
ugus
t 19
91 t
hrou
gh J
une
7993
--C
ontin
ued
[ft3/
s, c
ubic
feet
per
sec
ond;
col
/100
ml_,
col
onie
s pe
r 10
0 m
illili
ters
; --,
no
data
; <,
less
than
; >,
gre
ater
than
]
Co oo
Sam
plin
g da
te
07/2
0/92
08/0
3/92
06/2
2/93
Wea
ther
co
nditi
on
wet
wet dry
^a
Trio
r^
Rai
nfa"
am
°Unt
S
tream
flow
.
, .,
(inch
es)
(ft /
s)
rain
taii
17
.12
2.1
2.5
2.2
4 1.
36
17 71
6.7
2..
Tim
e (h
ours
)
1805
1840
1930
1430
1610
2035 --
Feca
l col
iform
(c
ol/1
00
mL)
160
'250
1,20
0
12,0
00
58,0
00
25,0
00
--
Fec
al
stre
ptoc
occu
s (c
ol/1
00
mL)
4,40
0
70,0
00
1,00
0
200,
000
130,
000
120,
000
H24
^on-
idea
l co
unt.
2Num
ber
of d
ry d
ays
and
stre
amfl
ow w
ere
not d
eter
min
ed b
ecau
se g
agin
g st
atio
ns w
ere
rem
oved
.
There are several other reasons for high bacteria counts in receding streamflow during storms. The soils in the Myrtle Beach area consist of a sandy topsoil and clayey subso; l (U.S. Department of Agriculture, 1986). As rainfall infiltrates the topsoil and reaches the subsoil, the clayey subsoil material retards infiltration; the topsoil quickly becomes saturated, and the excess rainfall runs off into the receiving streams. The high-water table in Myrtle Beach also acts as an impervious area (U.S. Department of Agriculture, 1986). After a time lag, the subsurface flow carrying fecal materials reaches streams during the receding streamflow. The high water table also can flood septic tanks that have drain fields connected to streams.
McDonald and Kay (1981) observed elsewhere that enteric-bacteria counts increase as river discharge increases. The relations of fecal coliform and fecal streptococcus bacteria counts to streamflow were plotted for stations on the Mainstem and KOA Branches (figs. 2 and 3). Enteric- bacteria counts at both stations tended to increase with increasing streamflow. The relations were weak, and factors other than streamflow could cause the relation to be complex. These factors include the number of dry days prior to a rain, climatic factors, and possible sources of contamination such as leaking septic tanks that release bacteria to the stream during dry weather. The relations did indicate that high enteric-bacteria counts were present at bare-flow conditions in the Mainstem and KOA Branches.
During the initial summer wet-weather sampling at the three gaging stationf, fecal coliform counts violated the State criteria for the class SFH waters in the water samples coHected. To determine the bacterial distribution, sampling was expanded to include additional site? in the Withers Swash Basin and 5 sites in the ocean and at a storm-water pipe that discharges directly on the beach that were sampled synoptically (fig. 4; table 20 at end of report). These data were needed to determine the source of high bacteria counts in the streams. Water samples were collected and examined for fecal coliform and fecal streptococcus bacteria.
The results of the additional data collection at the 51 sampling sites indicate that high enteric-bacteria counts are present during wet and dry weather. The highest count" were detected in water samples collected at the three gaging stations during high-flow conditions. The remaining 48 sites were sampled during dry weather or within a day after a storm. The specific locations of the high counts varied spatially and temporally, thus making it diffrult to determine the source of the bacteria. However, elevated bacteria counts are prevalent throughout the Withers Swash Basin.
Enteric-bacteria counts exceeding 2,000 col/100 mL were detected in almost every tributary of the basin (fig. 5). Enteric-bacteria counts exceeding 5,000 col/100 mL were detected at fewer locations (fig. 6). Along the KOA Branch, station 021107385 (site 41) was the only sampling site in which enteric-bacteria counts exceeded 5,000 col/100 mL. The Mainstem Branch contained the most sampling sites that exceeded 5,000 col/100 mL of enteric bacteria. Enteric-bacteria counts exceeding 10,000 col/100 mL were detected at the three gaging stations, along the Mainstem Branch, and at a sampling site located at the north end of Todd Street on tributary M-l (figs. 4 and 7). The sites where enteric-bacteria counts exceeded 10,000 col/100 mL were all located near Canal Drive near the Mainstem Branch.
No single source of fecal contamination was identified. High counts of fecal streptococcus indicate the contamination is relatively recent and large. Throughout the South Carolin? coast, many potential sources of fecal contamination exist, including pet, livestock and waterfowl feces, raw sewage from broken or leaking sewer lines, and liquids leaking from garbage containers (Lineback, 1986). It has long been suspected that failing septic tanks, improperly sited and maintained, are major sources of fecal coliform in the coastal zones even during periods between rains. Because the soils have a low permeability and the water table is high, the Myrtle
39
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78°5
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Figu
re 5
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Figu
re 6
. The
ent
eric
-bac
teria
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plin
g si
tes,
the
num
ber
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ampl
es c
olle
cted
, an
d th
e nu
mbe
r of
sam
ples
with
ente
ric-b
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ria c
ount
s gr
eate
r th
an 5
,000
col
onie
s pe
r 10
0 m
illili
ters
, W
ither
s S
was
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ea,
Myr
tle B
each
, S.
C.,
Aug
ust
1991
thr
ough
Jun
e 19
93.
26)f
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6/n
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AT
ION
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Figu
re 7
. The
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the
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ampl
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olle
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, an
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ric-b
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ount
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n 10
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, W
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Beach area is generally unsuited for septic fields (U.S. Department of Agriculture, 1986). The locations and number of septic tanks throughout the Withers Swash Basin were not available; therefore, it was not determined if septic tanks were the source of the fecal contamination. However, the high water table can create saturated zones within the soils that can harbor fecal coliform bacteria and allow them to multiply. In most water samples collected at the 51 sites, fecal coliform counts were higher than fecal streptococcus counts (tables 18,19, and 20).
Fecal coliform counts violated State criteria for class SFH waters in almost every sample collected; fecal streptococcus is not listed in State criteria for class SFH waters. If the source of fecal contamination is removed, fecal coliform and fecal streptococcus bacteria will eventually die off. The data suggest that fecal contamination in the Withers Swash Basin is extensive, and no one source is responsible. Septic tanks, illicit dischargers, and runoff from impervious areas are probably the major contributors of fecal contamination to the Withers Swash Basin.
Best Management Practices For Improved Water Quality
The implementation of best management practices (BMP's) can improve the water quality of a basin. There are source and structural control BMP's that are designed to prevent or remedy a problem that can lead to poor water quality. Reduced erosion, improved water quality, and protection of sensitive areas are some results of BMP's. This report can not adequately cover the numerous BMP's; therefore, the following discussion presents some basic strategies.
Source-control BMP's can include any practice that attacks the source of pollutants by reducing pollutant amounts accumulated on land surfaces, decreasing the amount of impervious areas within the basin to reduce runoff, and reduce or eliminate illicit discharges into storm drains and streams. The accumulation of pollutants on street surfaces can be minimized through education, regulations, and street cleaning. Educating the public in the proper disposal of household chemicals, oils, pesticides, and pet feces can be an effective starting point for a watershed-management plan. The enforcement of leash law, pet-waste cleanup, suburban livestock-control, and anti-dumping ordinances designed to reduce waste accumulation can help reduce pollutants washed into receiving waters. The cleaning of impervious areas also can help reduce accumulated pollutants. The cleaning may be done by sweeping, vacuuming, or flushing. Streetsweepers have been shown to redistribute the finer material to the gutters (Sartor and Boyd, 1972). By using a gutter broom and vacuum, some of the finer materials may be removed. If the streets are flushed, the water and contaminants should be removed before they enter the receiving streams. The catch basins also should be cleaned on regular basis. Zoning can be useful for restricting land development adjacent to stream banks, eliminating septic tanks near streams, or requiring vegetative buffer strips along stream banks. One of the most important source control is the elimination of illicit connections (U.S. Environmental Protection Agency, 1989). A survey of the entire basin can locate direct sanitary-sewer connections to the streams and sanitary-sewer leaks. Source controls are the easiest BMP's to implement as part of an overall watershed-management plan, although they are probably the least effective.
Structural controls can include detention and retention ponds, and vegetative controls. Detention and retention ponds are the most effective structures for reduction of nonpoint-source pollution into the receiving waters. These ponds reduce peak-flow rates, delay the release of runoff, reduce stream-bank erosion, and reduce pollutant concentration by dilution and bioremediation (U.S. Environmental Protection Agency, 1989). Vegetative controls are less costly than detention and retention ponds, and can be adequate in pretreating runoff in order to improve the effectiveness of other BMPs (U.S. Environmental Protection Agency, 1989). Vegetative controls can include basin landscaping, wetlands, grassed swales, and filter strips. As the only runoff-control practice, vegetative controls usually are inadequate.
46
A realistic approach to a watershed-management plan can include the application of BMP's to reduce nonpoint sources to a level at which water quality is improved or future degradation of the water resources is stopped. The Withers Swash Basin has similar characteristics to other swash basins near Myrtle Beach, and BMP's application to Withers Swash could be transferable to other basins.
SUMMARY
The objectives of this study were to investigate the water quality in Withers Swash, with emphasis on enteric bacteria, during the summer months of 1991,1992, and 1993. Withers Swash is located in the City of Myrtle Beach on the northern part of coastal South Carolina. The Withers Swash Basin is characterized by relatively flat coastal topography and includes two tributaries; the Mainstem and the KOA Branches. The Mainstem Branch is more urbanized than the KOA Branch, and drains commercial, single- and multi-family residential, and undeveloped land uses.
Three water-level gaging stations and two raingages were established in the study area. Stations were established on the Mainstem Branch, KOA Branch, and in the Withers Swash. A raingage was established on each of the two subbasins. Streamflow was determined by developing stage-discharge relations for the two upstream stations (Mainstem and KOA Branch). The downstream station, Withers Swash, had streamflow reversal at high tides; a stage- discharge relation was not developed. Water samples were collected and examined for over 200 chemical, physical, and biological constituents during base- and high-flow conditions. An intensive synoptic sampling for enteric bacteria at 51 sites also was completed. The results are presented as constituent values or concentrations at individual sampling sites and compared with State criteria for shellfish harvesting waters, and State Human Health criteria.
Some analytical results did not meet State criteria for shellfish harvesting waters or State Human Health criteria; these include some concentrations of dissolved oxygen, arsenic, lead, cadmium, mercury, 1,1,1-trichloroethane, 1,1-dichloroethylene, trichloroethylene, chlordane, dieldrin, and fecal coliform bacteria. Dissolved-oxygen concentrations were less than the State criterion for shellfish harvesting waters of 4.0 mg/L in 6 samples, and were lower than the daily minimum average of 5.0 mg/L in 18 of 27 samples. These concentrations are based on instantaneous measurements; data were insufficient to determine whether the mean concentration for each day was lower than 5.0 mg/L.
Concentrations of some trace elements detected at gaging stations violated State Human Health criteria. Arsenic was detected at a concentration of 7 ng/L in one sample, which exceeds the criterion of 1.4 |^g/L. Six of 12 samples collected at the gaging station on the KOA Branch, and 2 of 12 samples collected at the gaging station on the Mainstem Branch violated the criterion for lead of 50 |ig/L. Two of 12 samples collected from the gaging station on the KOA Branch violated the criterion for cadmium of 5 ng/L. Cadmium was detected in both samples at a concentration of 7 ng/L. Mercury concentrations exceeded the criterion (0.153 ng/L) in ten samples collected at the gaging station on the Mainstem Branch, five samples collected at the gaging station on the KOA Branch, and one sample collected at the gaging station on Withers Swash.
Volatile organic compounds and pesticides also were detected in concentrations that violated State Human Health criteria. These volatile organic compounds included 1,1,1-trichloroethane, 1,1-dichloroethylene, and trichloroethylene; the pesticides included chlordane and dieldrin. The volatile organic compounds in which concentrations violated criteria were all from water samples collected at the gaging station on the KOA Branch; whereas,
47
the concentrations of pesticide compounds that violated criteria were from water samples collected at the gaging station on the Mainstem Branch. Concentrations of 1,1,1-trichloroethane violated criteria in 2 of 8 samples; 1,1-dichloroethylene in 1 of 8 samples; and trichloroethylQne in all 8 samples collected from the gaging station on the KOA Branch.
The presence of trichloroethylene and its degradation products (dichloroethylene and vinyl chloride) in the KOA Branch during periods of base flow raises the possibility that a source of the products exists in the subsurface and is affecting the water quality of surface waters. The extent of the contamination is not known, because sampling of ground water was not included in the scope of this study. Chlordane and dieldrin were detected at the gaging station on the Mainstem Branch in concentrations violating State Human Health criteria. DDD and its by-products (DDE and DDT) also were detected at the gaging station on the Mainstem Branch. DDT and chlcrdane are no longer produced in the United States.
Fecal coliform bacteria counts did not meet the State criteria for shellfish harvesting waters during wet- and dry-weather sampling periods. These enteric bacteria were common throughout the Withers Swash Basin. Fifty-one sites were sampled synoptically for enteric bacteria during wet- and dry-weather conditions throughout the Withers Swash Basin, the Atlantic Ocean, and at a culvert discharging onto the beach. High bacteria counts varied spatially and temporally and could not be traced to a single source. The highest counts of enteric bacteria were measured at gaging stations on the Mainstem and KOA Branches. Enteric bacteria counts tended to increase as streamflow increased due to storm runoff. In some cases, enteric bacteria counts continued to increase as streamflow receded.
An initial washoff of pollutants from impervious areas may account for the initial rise in enteric-bacteria counts. As the streamflow increases, high velocities create turbid conditions that suspend small sediment particles carrying adsorbed enteric bacteria. These small particler tend to arrive at a downstream site during a period of highest discharge. Enteric bacteria tb at are adsorbed onto larger particles tend t& arrive at a downstream point as streamflow recedes.
There are other reasons for high bacteria counts during receding streamflow; these include clayey subsoils and high-water tables. Both clayey subsoils and high-water tables retard infiltration and, subsequently, increase surface runoff into receiving streams. The increased runoff that arrives at a downstream point as the stream is receding may carry fecal material from the soils and septic fields. The high water table also may flood septic tanks that have drain fields connected to streams.
Results from the synoptic-water sampling for enteric bacteria indicate that counts exceeding 10,000 col/100 mL were detected at the three gaging stations, sites along the Mainstem Branch, and at a site located at the north end of Todd Street on tributary M-l. The sites on the Mainstem Branch where counts exceeded 10,000 col/100 mL were all located near Canal E ~ive.
The implementation of best management practices can improve the water quality of the Withers Swash Basin. Source- and (or) structual-control best management practices can b^ used to prevent or remedy a problem that can lead to water-quality degradation. Source-control best management practices attack the source of pollutants by reducing pollutant amounts on land surfaces, reducing the amount of impervious areas, and reducing or eliminating illicit discharges into the storm drains and streams. These source controls can include education, regulatiors, and street cleaning. Structural controls include detention and retention ponds, and vegetative controls. Detention and retention ponds are the most effective structures for reduction of nonpoint-source pollution into receiving waters.
48
SELECTED REFERENCES
American Public Health Association, American Water Works Association, and Water Pollution Control Federation, 1989, Standard Methods for the Examination of Water and Waste water, (17th ed): Washington, D.C., American Public Health Association, method 5210 B.
Auer, M.T., and Niehaus, S.L., 1993, Modeling fecal coliform bacteria - I. Field and laboratory determination of loss kinetics: Water Research, v. 27, no. 4, p. 693-701.
Britton, L.J., and Greeson, P.E., eds., 1988, Methods for collection and analysis of rquatic biological and microbiological samples: U.S. Geological Survey Open-File Report 88-190, 685 p.
Clark, J.W., Viessman, W, Jr., and Hammer, M.J., 1977, Water Supply and Pollution Control, Third Edition: New York, Harper and Row Publishers, 857 p.
Espey, Huston, & Associates, Inc., 1988, Engineering and Environmental Studies for Withers Swash Project Area, Myrtle Beach, South Carolina, Appendix 1, Master Plan and Selected Feasibility Analysis, 24 p.
Fishman, M.J., and Friedman, L.C., 1985, Methods for determination of inorganic substances in water and fluvial sediments: U.S. Geological Survey Open-File Report 85-495, 709 p.
Fishman, M.J., and Friedman, L.C., 1989, Methods for determination of inorganic substances in water and fluvial sediments: U.S. Geological Survey Techniques of Water-Resources Investigations, book 5, chap. Al, 545 p.
Guy, H.P., and Norman, V.W., 1970, Field methods for measurement of fluvial sediment: U.S. Geological Survey Techniques of Water-Resources Investigations, book 3, chap. C2, 59 p.
Kay, David, and McDonald, Adrian, 1983, Predicting coliform concentrations in upland impoundments - Design and calibration of a multivariate model: Applied Environmental Sciences, 46(3), p 611-618.
Kennedy, E.J., 1984, Discharge ratings at gaging stations: U.S. Geological Survey Techniques of Water-Resources Investigations, book 3, chap. A10, 59 p.
Lineback, W.E., 1986, Review of the Effects of Nonpoint Source Pollution in Coastal Areas: S.C. Department of Health and Environmental Control, 30 p.
Lucius, J.E., Olhoeft, G.R., Hill, PL., and Duke, S.K., 1992, Properties and hazards of 108 selected substances -1992 Edition: U.S. Geological Survey Open-File Report 92-527, 554 p.
McDonald, Adrian, and Kay, David, 1981, Enteric Bacterial Concentrations in Reservoir Feeder Streams-Baseflow Characteristics and Response to Hydrograph Events: Water Resources, No. 15 (8), p. 961-968.
McDonald, Adrian, Kay, David, and Jenkins, Alien, 1982, Generation of fecal and total coliform surges by streamflow manipulation in the absence of normal hydrometeorological stimuli: Applied Environmental Sciences No. 44 (2), p. 292-300.
Moore, Gardner & Associates, Inc., 1980, Executive Summary: Final Evaluation of Stormwater Runoff: Control Alternatives, Consultants report prepared for Waccamaw Regional Planning and Development Council, p. I-l/VI-5.
Ollis, D.F., 1985, Contaminant Degradation in Water: Environmental Science Technology, v. 19, no. 6, p. 480-484.
49
SELECTED REFERENCES-Continued
Rantz, S.E. and others, 1982, Measurement and computation of streamflow: Volumes I and II, Measurement of stage and discharge: U.S. Geological Survey Water-Supply Paper 2175, 631 p.
Sartor, J.D., and Boyd, G.B., 1972, Water Pollution Aspects of Street Surface Contaminants: U.S. Environmental Protection Agency, EPA-R2-081 (NTIX PB-214408), 236 p.
Schillinger, J.E., and Cannon, J.J., 1982, Coliform attachment to suspended particles in storm water: The University of Michigan, Ann Arbor, Michigan, 42 p.
South Carolina Department of Health and Environmental Control, Office of Environmental Quality Control, 1993, Water Classification Standards (Regulation 61-68): Includes all amendments through May 28,1993,35 p.
Stecher, P.G., Finkel, M.J., Siegmund, O.H., and Szafranski, B.M., 1960, The Merck Index of Chemicals and Drugs, 7th edition: Rahway, N.J., Merck and Company, Inc., 1,641 p.
Stevens, H.H., Ficke, J.F., and Smoot, G.F., 1975, Water temperature-influential factors, field measurement, and data presentation: U.S. Geological Survey Techniques of Water- Resources Investigations, book 1, chap. Dl, 65 p.
U.S. Department of Agriculture, 1986, Soil Conservation Service: Soil Survey of Horry County, South Carolina, 137 p.
U.S. Environmental Protection Agency,1983, Methods for chemical analysis of water and wastewater: EPA-600/4-79-020, revised March 1983.
___1984, Method 625 Base/neutral and acids in Rules and regulations: Federal Register,October 26,1984, v. 49, no. 209, p. 153-174.
___1986, Quality criteria for water: U.S. Environmental Protection Agency, publication no. 440/5-86-001.
___1989, Urban Targeting and BMP Selection; An Information and Guidance Manual for State NPS Program Staff Engineers and Managers: EPA Contract No. 68-C8-0034, work assignment no. 0-1, amendment no. 1, 53 p.
Verschueren, Karel, 1983, Handbook of environmental data on organic chemicals, 2nd edition: New York, Van Nostrand Reinhold Co., 1,310 p.
Wershaw, R.L., Fishman, M.J., Grabbe, R.R., and Lowe, L.E., 1983, Methods for the deterrrination of organic substances in water and fluvial sediments: U.S. Geological Survey Open-File Report 82-1004,173 p.
___1987, Methods for the determination of organic substances in water and fluvial sediments: U.S. Geological Survey Techniques of Water-Resources Investigations, book 5, chap. A3, 80 p.
Wood, P.R., Lang, R.F., and Payan, I.L., 1985, Anaerobic Transformation, Transport and Removal of Volatile Chlorinated Organics in Ground Water: Ground Water Quality, p. 493-512.
50
Tabl
e 4.
--P
hysi
cal,
bact
eria
, an
d in
orga
nic
anal
yses
mad
e on
wat
er s
ampl
es c
olle
cted
at g
agin
g st
atio
ns in
the
With
ers
Sw
ash
Basi
n,
Myr
tle B
each
, S.
C.,
Sep
tem
ber
1991
thr
ough
Aug
ust
1992
[mg/
L, m
illig
ram
s pe
r lit
er;
ng/L
, m
icro
gram
s pe
r lit
er;
ft3/s
, cu
bic
feet
per
sec
ond;
urn
, m
icro
met
ers;
mL,
mill
ilite
rs;
, mic
rosi
emen
s pe
r ce
ntim
eter
; N
TU
, ne
phel
omet
ric t
urbi
dity
uni
ts;
°C,
degr
ees
Cel
sius
; --
, no
dat
a;co
l/100
mL,
col
onie
s pe
r 10
0 m
illili
ters
]
WA
TS
TO
RE
1 pa
ram
eter
cod
e
9041
0
0031
0
0034
0
0006
1
0090
0
0030
0
0040
3
9009
5
0007
6
0001
0
Con
stitu
ent
Phy
sica
l
Alk
alin
ity,
as C
aCO
s
Bio
chem
ical
oxy
gen
dem
and
(5-d
ay)
Che
mic
al o
xyge
n de
man
d
Dis
char
ge,
inst
anta
neou
s
Har
dnes
s, a
s C
aCO
s
Oxy
gen,
dis
solv
ed
pH,
labo
rato
ry
Spe
cific
con
duct
ance
, la
bora
tory
Tur
bidi
ty
Wat
er te
mpe
ratu
re
Ana
lytic
al m
etho
d2
Ele
ctro
met
rictit
ratio
n to
pH
4.5
--
Col
orim
etry
, K
2Cr2
O7
oxid
atio
n
Man
ual
Cal
cula
tion
Ele
ctro
met
ric -- -
Nep
helo
met
ric
Man
ual
Met
hod
num
ber
3I-1
030
-85
7521
0B
3l-3
561-
85
4..
3I-1
340
-85
6360
.1 - ~
3l-3
860-
85
3212
Uni
ts
mg/
L
mg/
L
mg/
L
ft3/s
mg/
L
mg/
L
Sta
ndar
d
nS/c
m
NTU °C
Det
ectio
n lim
it
0.1
mg/
L
.1 m
g/L
1 0
mg/
L
.01
ft3/s
1 m
g/L
.1 m
g/L
-- ~
1 N
TU
.1 °C
Tabl
e ^.
--P
hysi
cal,
bact
eria
, an
d in
orga
nic
anal
yses
mad
e on
wat
er s
ampl
es c
olle
cted
at g
agin
g st
atio
ns in
the
With
ers
Sw
ash
Basi
n,
Myr
tle B
each
, S.
C.,
Sep
tem
ber
1991
thr
ough
Aug
ust
7992
--C
ontin
ued
en
ro
[mg/
L, m
illig
ram
s pe
r lit
er; j
ig/L
, m
icro
gram
s pe
r lit
er; f
t3/s
, cu
bic
feet
per
sec
ond;
^m
, m
icro
met
ers;
mL,
mill
ilite
rs;
, mic
rosi
emen
s pe
r cen
timet
er;
NTU
, ne
phel
omet
ric tu
rbid
ity u
nits
; °C
, deg
rees
Cel
sius
; -,
no d
ata;
col/1
00 m
L, c
olon
ies
per
100
mill
ilite
rs]
WA
TS
TO
RE
1 pa
ram
eter
cod
e
3162
5
3167
3
0061
0
7184
5
0062
5
0109
7
0100
2
0101
2
0102
7
Con
stitu
ent
Bac
teria
Feca
l col
iform
bac
teria
Feca
l stre
ptoc
occu
s ba
cter
ia Inor
gani
c
Am
mon
ia n
itrog
en, t
otal
Am
mon
ia n
itrog
en, t
otal
, as
NH
4
Am
mon
ia p
lus
orga
nic
nitro
gen,
tota
l
Ant
imon
y, to
tal
Ars
enic
, tot
al
Ber
ylliu
m, t
otal
Cad
miu
m, t
otal
Ana
lytic
al m
etho
d2
Mem
bran
e fil
ter,
0.7
urn,
M-F
C
med
ia a
t 44.
5 °C
Mem
bran
e fil
ter,
0.45
urn
imm
edia
te
incu
batio
n, M
F, K
Fag
ar
Col
orim
etry --
Blo
ck d
iges
tion
and
colo
rimet
ry
AA
S
AAS,
hyd
ride
AA
S
AAS
Met
hod
num
ber
Uni
ts
5B-0
050-
85
col/1
00
mL
5B-0
055-
85
col/1
00
mL
3l-4
522-
85
mg/
L
mg/
L
3l-4
552-
85
mg/
L
3l-3
055-
85
ng/L
3l-4
062-
85
ng/L
3l-3
095-
85
ng/L
3!-3
1 35
-35
ng/L
Det
ectio
n lim
it
10 c
ol/1
00
mL
10 c
ol/1
00
mL
.01
mg/
L
.01
mg/
L
.2
mg/
L
1 ng
/L
1 ng
/L
1 0
ng/L
10
H
i/!
i <J
Jiy.
L.
Tabl
e 4.
--P
hysi
cal,
bact
eria
, an
d in
orga
nic
anal
yses
mad
e on
wat
er s
ampl
es c
olle
cted
at g
agin
g st
atio
ns in
the
With
ers
Sw
ash
Basi
n,
Myr
tle B
each
, S.
C.,
Sep
tem
ber
1991
thr
ough
Aug
ust
7992
--C
ontin
ued
[mg/
L, m
illig
ram
s pe
r lit
er;
fig/L
, m
icro
gram
s pe
r lit
er; f
r/Vs,
cub
ic fe
et p
er s
econ
d; f
im,
mic
rom
eter
s; m
L, m
illili
ters
;
fiS/c
m,
mic
rosi
emen
s pe
r ce
ntim
eter
; N
TU,
neph
elom
etric
turb
idity
uni
ts;
°C,
degr
ees
Cel
sius
; --,
no
data
;co
l/100
mL,
col
onie
s pe
r 10
0 m
illili
ters
]
WA
TSTO
RE
1 pa
ram
eter
cod
e
0091
5
0094
0
0103
4
0104
2
0072
0
0105
1
0092
5
7190
0
0106
7
0060
0
0062
0
. 00
615
Con
stitu
ent
Inor
gani
c-co
ntin
ued
Cal
cium
, di
ssol
ved
Chl
orid
e, d
isso
lved
Chr
omiu
m,
tota
l
Cop
per,
tota
l
Cya
nide
, to
tal
Lead
, tot
al
Mag
nesi
um,
diss
olve
d
Mer
cury
, to
tal
Nic
kel,
tota
l
Nitr
ogen
, to
tal
Nitr
ate
nitro
gen,
tot
al
Nitr
ite n
itrog
en,
tota
l
Ana
lytic
al m
etho
d2
AE
, IC
P
1C DC
pla
sma
AA
S
Col
orim
etry
, ba
rbitu
ric a
cid
AA
S,
grap
hite
fu
rnac
e
AE
, IC
P
AA
S,
flam
eles
s
AA
S,
grap
hite
fu
rnac
e
Cal
cula
tion
Cal
cula
tion
Col
orim
etry
, di
azot
izat
ion
Met
hod
num
ber
3I- 1
472-
85
3l-2
058-
85
3l-3
229-
87
3l-3
270-
85
3l-4
302-
85
3l-3
403-
89
3I-1
472
-85
3l-3
462-
85
3l-3
503-
89
- -
3l-4
540-
85
Uni
ts
mg/
L
mg/
L
H9/
L
ng/L
mg/
L
H9/
L
mg/
L
H9/
L
H9/
L
mg/
L
mg/
L
mg/
L
Det
ectio
n lim
it
0.02 .0
1
10 10
.01
1 .01
.1 1 .1 .01
0.01
mg/
L
mg/
L
W3/
L
H9/
L
mg/
L
H9/
L
mg/
L
H9/
L
H9/
L
mg/
L
mg/
L
mg/
L
Tabl
e 4.
-Phy
sica
l, ba
cter
ia,
and
inor
gani
c an
alys
es m
ade
on w
ater
sam
ples
col
lect
ed a
t gag
ing
stat
ions
in th
e W
ither
s S
was
h Ba
sin,
M
yrtle
Bea
ch,
S.C
., S
epte
mbe
r 19
91 t
hrou
gh A
ugus
t 79
92-C
ontin
ued
[mg/
L, m
illig
ram
s pe
r lit
er;
ng/L
, m
icro
gram
s pe
r lit
er; f
r/Vs,
cub
ic fe
et p
er s
econ
d; j^
m,
mic
rom
eter
s; m
l, m
illili
ters
;nS
/cm
, m
icro
siem
ens
per
cent
imet
er;
NTU
, ne
phel
omet
ric tu
rbid
ity u
nits
; °C
, de
gree
s C
elsi
us;
--, n
o da
ta;
col/1
00 m
l_, c
olon
ies
per
100
mill
ilite
rs]
WA
TSTO
RE
1 pa
ram
eter
cod
e
0063
0
7050
7
0065
0
0066
5
0093
5
0051
5
0053
0
0114
7
0093
0
0107
7
Con
stitu
ent
Inor
gani
c-co
ntin
ued
Nitr
ite p
lus
nitra
te n
itrog
en,
tota
l
Orth
opho
spha
te,
tota
l, as
P
Pho
spha
te,
tota
l
Pho
spho
rus,
tot
al
Pot
assi
um,
diss
olve
d
Res
idue
at
1 05
°C,
diss
olve
d
Res
idue
at
1 05
°C,
susp
ende
d
Sel
eniu
m, t
otal
Sod
ium
, di
ssol
ved
Silv
er,
tota
l
Ana
lytic
al m
etho
d2
Col
orim
etry
, C
d-
redu
ctio
n
Col
orim
etry
, ph
osph
omol
ybda
te
--
Col
orim
etry
, ph
osph
omol
ybda
te
AA
S
Gra
vim
etric
Gra
vim
etric
AA
S
AE
, IC
P
AA
S,
grap
hite
fu
rnac
e
Met
hod
num
ber
3l-4
545-
85
3l-4
601-
85
--
3l-4
600-
85
3I-1
630
-85
3I-1
749
-85
3l-3
765-
85
3l-4
667-
85
3I-1
472
-85
3l-3
724-
89
Uni
ts
mg/
L
mg/
L
mg/
L
mg/
L
mg/
L
mg/
L
mg/
L
ng/L
mg/
L
W/L
Det
ectio
n lim
it
.1 m
g/L
.01
mg/
L
.01
mg/
L
.01
mg/
L
.01
mg/
L
1 m
g/L
1 m
g/L
1 ng
/L
.2
mg/
L
1 W
/\-
en Oi
Tabl
e ^.
--P
hysi
cal,
bact
eria
, and
inor
gani
c an
alys
es m
ade
on w
ater
sam
ples
col
lect
ed a
t gag
ing
stat
ions
in th
e W
ither
s S
was
h Ba
sin,
M
yrtle
Bea
ch,
S.C
., S
epte
mbe
r 19
91 t
hrou
gh A
ugus
t 79
92-C
ontin
ued
[mg/
L, m
illig
ram
s pe
r lit
er;
|ig/L
, m
icro
gram
s pe
r lit
er; f
t^s,
cub
ic fe
et p
er s
econ
d; u
rn,
mic
rom
eter
s; m
L, m
illili
ters
;jiS
/cm
, m
icro
siem
ens
per
cent
imet
er;
NTU
, ne
phel
omet
ric tu
rbid
ity u
nits
; °C
, de
gree
s C
elsi
us;
--, n
o da
ta;
col/1
00 m
L, c
olon
ies
per
100
mill
ilite
rs]
WA
TSTO
RE
1 pa
ram
eter
cod
e
7030
1
7030
0
0094
5
0007
6
0109
2
Con
stitu
ent
Inor
gani
c-co
ntin
ued
Sol
ids,
sum
of c
onst
ituen
ts,
diss
olve
d
Sol
ids,
Res
idue
at
1 80
°C,
diss
olve
d
Sul
fate
, dis
solv
ed
Turb
idity
Zinc
, to
tal
Ana
lytic
al m
etho
d2
Cal
cula
tion
Gra
vim
etric
1C Nep
helo
met
ric
AA
S
Met
hod
num
ber
3l-1
751-
85
3I-1
750
-85
3l-2
058-
85
3l-3
860-
85
3l-5
900-
85
Uni
ts
mg/
L
mg/
L
mg/
L
NTU W3/
L
Det
ectio
n lim
it
1 1 .01
1 10
mg/
L
mg/
L
mg/
L
NTU H9/
L
'Nat
iona
l Wat
er D
ata
Stor
age
and
Ret
riev
al S
yste
m o
f the
U.S
. Geo
logi
cal S
urve
y.2A
AS,
ato
mic
abs
orpt
ion
spet
rom
etry
; AE
, ato
mic
em
issi
on;
1C, i
on c
hrom
atog
raph
; IC
P, i
nduc
tivel
y co
uple
d pl
asm
a; D
C, d
irec
t cur
rent
; M
F, m
embr
ane
filtr
atio
n.3F
ishm
an a
nd F
ried
man
, eds
., (1
989)
.4R
antz
and
oth
ers
(198
2).
5Bri
tton
and
Gre
eson
, ed
s., (
1988
).6U
.S. E
nvir
onm
enta
l Pro
tect
ion
Age
ncy
(198
3).
7Am
eric
an P
ublic
Hea
lth A
ssoc
iatio
n (1
989)
.
Table ^.-Organic compounds and detection limits for analyses made on water samples collected at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992
[All concentrations in micrograms per liter except where indicated; DDE, dichlorodiphenylchloroethylene;DOT, dichlorodiphenyltrichloroethane; ODD, dichlorodiphenyldichloroethane; PCN, polychlorinated
naphthalene; PCB, polychlorinated biphenyl; BHC, benzene hexachloride]
WATSTORE 1 Code Compounds Detection Limit
Gross
00680
00605
Total organic carbon
Organic nitrogen, total
0.1 mg/L
.1 mg/L
Acid extractables2' 3 ' 4
34452
34586
82626
34601
34606
34657
34616
34591
34646
39032
34694
34621
32730
p-Chloro-meta-cresol
2-Chlorophenol
1 ,2-Diphenylhydrazine
2,4-Dichlorophenol
2,4-Dimethylphenol
4,6-Dinitro-o-cresol
2,4-Dinitrophenol
2-Nitrophenol
4-Nitrophenol
Pentachlorophenol
Phenol
2,4,6-Trichlorophenol
Phenols, total
30
5
5
5
5
30
20
20
5
30
5
20
1
Neutral extractables3 ' 4< 5
34396
39702
39700
34278
34696
34581
Hexachloroethane
Hexachlorobutadiene
Hexachlorobenzene
bis (2-Chloroethoxy) methane
Naphthalene
2-Chloronaphthalene
5
5
5
5
5
5
56
Table 5.--Organic compounds and detection limits for analyses made on water samples collected at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 7992--Continued
[All concentrations in micrograms per liter except where indicated; DDE, dichlorodiphenylchloroethylene;DOT, dichlorodiphenyltrichloroethane; ODD, dichlorodiphenyldichloroethane; PCN, polychlorinated
naphthalene; PCB, polychlorinated biphenyl; BHC, benzene hexachloride]
WATSTORE 1 Code Compounds Detection Limit
Neutral extractables3 ' 4> 5 --Continued
34408
34447
34611
34626
34636
39100
34596
34341
00556
34336
39110
34200
34205
34292
34381
34376
34320
34469
34461
34220
34526
34230
34242
34247
34403
Isophorone
Nitrobenzene
2,4-Dinitrotoluene
2,6-Dinitrotoluene
4-Bromophenylphenyl ether
bis (2-Ethylhexy) phthalate
di-n-Octylphthalate
Dimethylphthalate
Oil and grease
Diethylphthalate
di-n-Butylphthalate
Acenaphthylene
Acenaphthene
n-Butylbenzylphthalate
Fluorene
Fluoranthene
Chrysene
Pyrene
Phenanthrene
Anthracene
Benzo (a) anthracene
Benzo (b) fluoranthene
Benzo (k) fluoranthene
Benzo (a) pyrene
Indeno (1 ,2,3-cd) pyrene
5
5
5
5
5
5
10
5
1
5
5
5
5
5
5
5
10
5
5
5
10
10
10
10
10
57
Table 5.--Organic compounds and detection limits for analyses made on water samples collected at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 7992-Continued
[All concentrations in micrograms per liter except where indicated; DDE, dichlorodiphenylchloroethylene;DOT, dichlorodiphenyltrichloroethane; ODD, dichlorodiphenyldichloroethane; PCN, polychlorinated
naphthalene; PCB, polychlorinated biphenyl; BHC, benzene hexachloride]
WATSTORE' Code Compounds Detection Limit
Neutral extractables3 ' 4' 5-Continued
34556
34521
34641
34273
34386
34283
Dibenzo (a,h) anthracene
Benzo (g,h,i) perylene
4-Chlorophenylphenyl ether
bis (2-Chloroethyl) ether
Hexachlorocyclopentadiene
bis (2-Chloroisopropyl)ether
10
10
5
5
5
5
Base extractables3 ' 4' 5
34631
39120
34433
34438
34428
3,3 '-Dichlorobenzidine
Benzidine
n-Nitrosodiphenylamine
n-Nitrosodimethylamine
n-Nitroso-n-propylamine
25
50
5
5
5
Organochlorine pesticides6- 7< 8 ' 9
39330
39380
39365
39370
39360
39390
34366
39410
39420
39350
39400
39250
Aldrin
Dieldrin
DDE
DDT
DDD
Endrin
Endrin aldehyde
Heptachlor
Heptachlor epoxide
Chlordane
Toxaphene
PCN's, total
.01
.01
.01
.01
.01
.01
.01
.01
.01
.1
1
.1
58
Table ^.--Organic compounds and detection limits for analyses made on water samples collected, at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August /9&?--Continued
[All concentrations in micrograms per liter except where indicated; DDE, dichlorodiphenylchloroethvlene;DDT, dichlorodiphenyltrichloroethane; DDD, dichlorodiphenyldichloroethane; PCN, polychlorincted
naphthalene; PCB, polychlorinated biphenyl; BHC, benzene hexachloride]
WATSTORE 1 Code Compounds Detection Limit
Organochlorine pesticides6- 7> 8- 9-Continued
39516
39337
39338
34259
39340
39034
39755
39480
39065
39062
39310
39320
39300
39388
34361
34356
34351
34671
39488
39492
39496
39500
39504
39508
RGB's, total
alpha-BHC (benzene hexachloride)
beta-BHC (benzene hexachloride)
delta-BHC (benzene hexachloride)
Lindane (gamma-BHC)
Ethylan (Perthane)
Mi rex
Methoxychlor
trans-Chlordane
cis-Chlordane
p,p'-DDD
p,p'-DDE
p,p'-DDT
Endosulfan
Endosulfan I
beta-Endosulfan
Endosulfan sulfate
Aroclor1016PCB
Aroclor1221 PCB
Aroclor 1232 PCB
Aroclor 1242 PCB
Aroclor 1248 PCB
Aroclor 1254 PCB
Aroclor 1260 PCB
0.1
.1
.1
.1
.1
.1
.01
.01
.10
.10
.10
.10
.10
.01
.1
.04
.6
.1
1
.1
.1
.1
.1
.1
59
Table 5.--Organic compounds and detection limits for analyses made on water samples collected at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 7992--Continued
[All concentrations in micrograms per liter except where indicated; DDE, dichlorodiphenylchloroeth'lene;DOT, dichlorodiphenyltrichloroethane; ODD, dichlorodiphenyldichloroethane; PCN, polychlorinfted
naphthalene; PCB, polychlorinated biphenyl; BHC, benzene hexachloride]
WATSTORE 1 Code Compounds Detection Limit
Volatile organics 10
34010
34030
34371
32102
34301
32103
34506
34704
34699
34496
34501
34511
34516
34311
34576
32106
34541
34423
34418
34413
32101
32105
34475
39180
39175
Toluene
Benzene
Ethylbenzene
Carbon tetrachloride
Chlorobenzene
1 ,2-Dichloroethane
1,1,1-Trichloroethane
cis-1 ,3-Dichloropropene
trans-1 ,3-Dichloropropene
1,1-Dichloroethane
1,1-Dichloroethylene
1 ,1 ,2-Trichloroethane
1 ,1 ,2,2-Tetrachloroethane
Chloroethane
2-Chloroethylvinylether
Chloroform
1 ,2-Dichloropropane
Methylene chloride
Methyl chloride
Methyl bromide
Dichlorobromomethane
Chlorodibromomethane
Tetrachloroethylene
Trichloroethylene
Vinyl chloride
0.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
60
Table 5,-Organic compounds and detection limits for analyses made on water samples collec^d at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992~Cont\nued
[All concentrations in micrograms per liter except where indicated; DDE, dichlorodiphenylchloroethylene;DDT, dichlorodiphenyltrichloroethane; DDD, dichlorodiphenyldichloroethane; PCN, polychlorin^ted
naphthalene; PCS, polychlorinated biphenyl; BHC, benzene hexachloride]
WATSTORE 1 Code Compounds Detection Limit
Volatile organics 10~Continued
34546
32104
77128
81551
34536
34566
34571
77562
77168
77613
77443
34551
77222
77275
77651
34561
77226
77173
77277
77170
34210
34215
81555
77093
82625
1 ,2-trans-Dichloroethene
Bromoform
Styrene
Xylene
o-Chlorobenzene
1 ,3-Dichlorobenzene
1 ,4-Dichlorobenzene
1,1,1 ,2-Tetrachloroethane
1,1-Dichloropropene
1 ,2,3-Trichlorobenzene
1 ,2,3-Trichloropropane
1 ,2,4-Trichlorobenzene
Pseudocumene
o-Chlorotqluene
1 ,2-Dibromoethane
1 ,3-Dichloropropene
Mesitylene
1 ,3-Dichloropropane
p-Chlorotoluene
2,2-Dichloropropane
Acrolein
Acrylonitrile
Bromobenzene
cis-1 ,2-Dichloroethene
Dibromochloropropane
0.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
61
Table 5.--Organic compounds and detection limits for analyses made on water samples collected at gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 7992-Continued
[All concentrations in micrograms per liter except where indicated; DDE, dichlorodiphenylchloroe*hylene;DDT, dichlorodiphenyltrichloroethane; DDD, dichlorodiphenyldichloroethane; PCN, polychloririted
naphthalene; PCB, polychlorinated biphenyl; BHC, benzene hexachloride]
WATSTORE 1 Code Compounds Detection Limit
Volatile organics 10--Continued
30217
34668
39702
77223
77342
77224
34696
77356
77350
77353
34488
Dibromomethane
Dichlorodifluoromethane
Hexachlorobutadiene
iso-Propylbenzene
n-Butylbenzene
n-Propylbenzene
Naphthalene
p-lsopropyltoluene
sec-Butylbenzene
tert-Butylbenzene
Trichlorofluoromethane
0.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
.2
'National Water Data Storage and Retrieval System of the U.S. Geological Survey.
2Method 0-3117-83 (Wershaw and others, 1987).
3Method 625 (U.S. Environmental Protection Agency, 1984).
4Method 0-5116-83 (Wershaw and others, 1987).
5Method 0-3118-83 (Wershaw and others, 1987).
6Method 608 (U.S. Environmental Protection Agency, 1984).
7Method 0-3104-83 (Wershaw and others, 1987).
8Method 0-1104-83 (Wershaw and others, 1987).
9Method 0-5104-83 (Wershaw and others, 1987).
10Method 0-3115-83 (Wershaw and others, 1987).
62
Tabl
e 20
.-R
esul
ts o
f bac
teria
sam
plin
g at
var
ious
loca
tions
with
in th
e W
ither
s S
was
h B
asin
and
in th
e A
tlant
ic O
cean
nea
r the
mou
th o
f With
ers
Swas
h, M
yrtle
Bea
ch,
S.C
., A
ugus
t 19
91 t
hrou
gh J
une
1993
[Col
/100
ml_,
col
onie
s pe
r 10
0 m
illilit
ers;
W, w
est;
Ave
., av
enue
; N,
nor
th; S
, sou
th; U
S, U
nite
d S
tate
s; H
wy.
, hi
ghw
ay;
X, in
ters
ectio
n; -
-, no
dat
a;(K
), de
note
s a
non-
idea
l cou
nt; S
t., S
treet
; ft,
feet
; N
E, n
orth
east
; SE,
sou
thea
st; S
W, s
outh
wes
t; NW
, no
rthw
est;
<, le
ss th
an; S
C, S
outh
Car
olin
a;R
t, ro
ute;
ext
, ex
tens
ion;
E, e
ast;
Rd.
, roa
d; M
B, M
yrtle
Bea
ch;
USG
S, U
.S.
Geo
logi
cal S
urve
y; >
, gre
ater
than
; Bl
vd, b
oule
vard
]
Iden
tifi
ca
tion
Stat
ion
...
Wat
erco
urse
nu
mbe
r nu
mbe
r(f
ig. 4
)
1 02
1107
370.
970
Mai
nste
m
Bra
nch
2 02
1107
370.
980
Mai
nste
m
Bra
nch
3 02
1107
370.
985
Unn
amed
tr
ibut
ary
to
Mai
nste
m
Bra
nch
4 02
1107
370.
990
Mai
nste
m
Bra
nch
5 02
1107
370.
995
Unn
amed
tr
ibut
ary
to
Mai
nste
m
Bra
nch
6 02
1107
371.
980
Mai
nste
m
Bra
nch
.
. .
n
Tim
e Fe
cal c
ohfo
rm
Site
loc
atio
n D
ate
., .
/ 1/
IAn
_.
(hou
rs)
(col
/ 1 0
0 m
L)
W s
ide
of 1
0th
Ave
. 11
/07/
91
--
280
(K)
N,S
sid
e of
US
Hw
y.
17 B
ypas
s/ 1 O
th A
ve.
NX
N s
ide
of S
eabo
ard
11/0
7/91
-
80 (K
) St
., 25
0 ft
W o
f Sea
- 06
/1 5
/92
1 ,20
0 bo
ard
St./
1 Oth
Ave
.N
X
!,30
0ftN
Eof
Oce
ola
06/1
5/92
--
87
0 St
VlO
th A
ve. N
X;
200
ft SE
of C
oast
al
Lan
e/O
ceol
a St
. X
400
ft W
of
10th
Ave
. 06
/15/
92
-- 1,
300
N, 5
00 f
t SW
of t
he
Seab
oard
St./
1 Oth
A
ve. N
X
On
the
SE s
ide
of
06/1
5/92
-
700
Oce
olaS
t., 1
, 200
ft
NE
oft
heX
of
Oce
olaS
t. an
d 10
thA
ve.N
900
ft up
stre
am f
rom
06
/15/
92
- 1,
500
0211
0737
1.99
0;
Feca
l st
rept
ococ
cus
Rem
arks
(c
ol/ 1
00
mL)
40 (K
)
200
(K)
640
140
1,20
0
2,00
0
2,50
0
!,O
OO
ftS
Wof
theX
of
I Ot
h A
ve.
Nan
d O
ceol
a St
.
Tabl
e 2
0.-
Res
ults
of b
acte
ria s
ampl
ing
at v
ario
us lo
catio
ns w
ithin
the
With
ers
Sw
ash
Bas
in a
nd in
the
Atla
ntic
Oce
an n
ear t
he m
outh
of W
ither
s Sw
ash,
Myr
tle B
each
, S.
C.,
Aug
ust
1991
thr
ough
Jun
e 79
93-C
ontin
ued
[Col
/100
ml,
colo
nies
per
100
milli
liter
s; W
, wes
t; A
ve.,
aven
ue;
N, n
orth
; S, s
outh
; U
S, U
nite
d S
tate
s; H
wy.
, hi
ghw
ay; X
, int
erse
ctio
n; -
-, no
dat
a;(K
), de
note
s a
non-
idea
l cou
nt; S
t., S
treet
; ft,
feet
; N
E, n
orth
east
; SE,
sou
thea
st; S
W, s
outh
wes
t; N
W, n
orth
wes
t; <,
less
than
; SC
, Sou
th C
arol
ina;
Rt.,
rou
te; e
xt.,
exte
nsio
n; E
, eas
t; R
d., r
oad;
MB,
Myr
tle B
each
; US
GS
, U
.S. G
eolo
gica
l Sur
vey;
>, g
reat
er th
an;
Blvd
, bou
leva
rd]
Iden
tifi
catio
n St
atio
n .
,
, W
ater
cour
se
num
ber
num
ber
(fig
- 4) 7
0211
0737
1.98
5 U
nnam
edtri
buta
ry to
Mai
nste
mB
ranc
h
8 02
1107
371.
990
Mai
nste
mB
ranc
h
9 02
1107
371.
995
Unn
amed
tribu
tary
toM
ains
tem
Bra
nch
10
0211
0737
2.95
0 M
ains
tem
Bra
nch
11
0211
0737
2.96
0 M
ains
tem
Bra
nch
Site
loca
tion
At t
he N
end
of C
anal
St.,
just
N o
f the
end
of th
e ro
ad
500
ft W
of C
anal
St.,
200
ft N
W o
f the
recr
eatio
n ce
nter
and
75 f
t W o
f02
1107
371.
995
200
ft N
W o
f the
poo
lat
the
Can
al S
t.re
crea
tion
cent
er,
400
ft W
of C
anal
St.
in a
sm
all t
ribut
ary
toth
e M
ains
tem
Bra
nch
400
ft W
of C
anal
St.,
near
the
mid
dle
of th
eW
sid
e of
the
recr
eat
ion
cent
er;
1 00
ftN
W o
f site
0211
0737
2.96
0,at
a p
ipe
outfa
ll
400
ft W
of C
anal
St.,
at th
e SW
cor
ner o
fth
e re
crea
tion
cent
er
Tim
e D
ate
. (hou
rs)
08/0
1/91
06/1
7/92
08/0
4/92
06/1
7/92
06/1
7/92
09/1
0/91
11/0
7/91
06/1
7/92
06/1
8/92
08/0
5/92
08/0
1/91
06/1
5/92
08/0
4/92
06/2
3/93
Feca
l col
iform
(c
ol/1
00
mL)
4,00
0 (K
)7,
000
6,00
0
1,10
0(K
)
1,30
0(K
)
~
600
(K)
21,0
00 <70
150(
K)
25,0
00 (K
)3,
200
6,60
0 41
Feca
l st
rept
ococ
cus
(col
/lOO
mL)
1,30
02,
100
9,30
0
800
(K)
900
(K)
2,00
0 80 (K
)1,
200(
K)
<70
<50
860
8,10
04,
700 36
Rem
arks
__ - --
Take
n fr
om s
mal
l poo
l bel
owpi
pe o
utflo
w.
Take
n fr
om w
ater
drip
ping
off
soil
belo
w p
ipe
outfa
ll.Ta
ken
stra
ight
from
pip
e ou
tfa
ll.Ta
ken
from
sm
all p
ool b
elow
pipe
out
fall.
~
Tabl
e 20
.--R
esul
ts o
f bac
teria
sam
plin
g at
var
ious
loca
tions
with
in th
e W
ither
s S
was
h B
asin
and
in th
e A
tlant
ic O
cean
nea
r the
mou
th o
f With
ers
Swas
h, M
yrtle
Bea
ch,
S.C
., A
ugus
t 19
91 t
hrou
gh J
une
7993
--Con
tinue
d
[Col
/100
ml_
, col
onie
s pe
r 10
0 m
illili
ters
; W, w
est;
Ave.
, ave
nue;
N, n
orth
; S,
sou
th;
US,
Uni
ted
Sta
tes;
Hw
y.,
high
way
; X,
inte
rsec
tion;
--, n
o da
ta;
(K),
deno
tes
a no
n-id
eal c
ount
; St.,
Stre
et; f
t, fe
et;
NE,
nor
thea
st;
SE, s
outh
east
; SW
, sou
thw
est;
NW
, no
rthw
est;
<, le
ss th
an; S
C,
Sout
h C
arol
ina;
Rt.,
rou
te; e
xt.,
exte
nsio
n; E
, eas
t; R
d., r
oad;
MB,
Myr
tle B
each
; U
SGS,
U.S
. Geo
logi
cal S
urve
y; >
, gre
ater
than
; Bl
vd, b
oule
vard
]
Iden
tifi
catio
n nu
mbe
r (fi
g- 4
)
Stat
ion
num
ber
Wat
erco
urse
Site
loca
tion
Dat
eT
ime
(hou
rs)
Feca
l col
ifor
m
(col
/lOO
mL
)
Feca
lst
rept
ococ
cus
(col
/lOO
mL
)R
emar
ks
8;
12
0211
0737
2.97
0 M
ains
tem
A
t the
woo
den
Bra
nch
railr
oad
brid
ge, 3
00 ft
W
of C
anal
St.,
500
ft
N o
f the
Can
al S
t./
US
Hw
y. 5
01 X
13
0211
0737
2.97
5 M
-l
600
ft W
of S
C R
t. 84
(3rd
Ave
. S e
xt),
1,00
0 ft
N o
f Bro
ad
way
St.
(Old
Con
way
H
wy.
), 30
0 ft
E of
C
anno
n R
d.
14
0211
0737
2.98
0 M
ains
tem
O
n th
e SW
sid
e of
US
Bra
nch
Hw
y. 5
01, 5
0 ft
NW
of
the
3rd
Ave
. NX
15
0211
0737
2.98
5 M
-l
On
the
W s
ide
of S
CR
t. 84
(3r
d A
ve.
S ex
t), 1
,000
ft N
of t
he
Bro
adw
ay S
t. (O
ld
Con
way
Hw
y.)
X in
fr
ont o
f Mun
icip
al
wel
l fac
ility
#21
16
0211
0737
2.99
0 M
ains
tem
A
t the
bri
dge
onB
ranc
h C
edar
St,
500
ft W
of
the
3rd
Ave
. N X
08/0
4/92
08
/05/
92
06/2
3/93
08/0
5/92
08/0
4/92
06
/23/
93
08/0
4/92
08
/05/
92
08/0
1/91
09
/10/
91
11/0
6/91
08
/04/
92
06/2
3/93
25,0
00
250
(K)
22
1,20
0
$,80
0 73
1,10
0(K
) 1,
600
2,50
0 (K
)
730
5,00
0 81
5,50
01,
000 20
1,10
0
7,50
0 44
5,70
0 1,
400(
K)
2,00
01,
400
230
3,60
0 22
Tabl
e 20
.--R
esul
ts o
f bac
teria
sam
plin
g at
var
ious
loca
tions
with
in th
e W
ither
s S
was
h B
asin
and
in th
e A
tlant
ic O
cean
nea
r the
mou
th o
f With
ers
Swas
h, M
yrtle
Bea
ch,
S.C
., A
ugus
t 19
91 t
hrou
gh J
une
/993
~Con
tinue
d
[Col
/100
ml,
colo
nies
per
100
mill
ilite
rs; W
, wes
t; Av
e., a
venu
e; N
, nor
th;
S, s
outh
; US,
Uni
ted
Sta
tes;
Hw
y,,
high
way
; X, i
nter
sect
ion;
--,
no d
ata;
(K),
deno
tes
a no
n-id
eal c
ount
; St.,
Stre
et; f
t, fe
et;
NE,
north
east
; SE,
sou
thea
st; S
W, s
outh
wes
t; N
W,
north
wes
t; <f
less
than
; SC
, Sou
th C
arol
ina;
Rt.,
rou
te; e
xt.,
exte
nsio
n; E
, eas
t; R
d., r
oad;
MB,
Myr
tle B
each
; US
GS
, U
.S. G
eolo
gica
l Sur
vey;
>, g
reat
er th
an; B
lvd,
bou
leva
rd]
Iden
tifi
catio
n St
atio
n nu
mbe
r nu
mbe
r (f
ig. 4
)
17
0211
0737
2.99
5
18
0211
0737
4.96
0
19
0211
0737
4.97
0
20
0211
0737
4.98
0
21
0211
0737
4.99
0
Wat
erco
urse
M-l
Unn
amed
trib
utar
y to
M-2
Unn
amed
trib
utar
y to
M-2
Unn
amed
trib
utar
y to
M-2
Unn
amed
trib
utar
y to
M-2
Site
loc
atio
n
At t
he N
end
of
Todd
St.
At t
he N
W e
nd o
f20
th A
ve. N
, whe
reth
e pa
ved
road
end
s
On
the
NE
side
of
2 1 s
t Ave
. N, a
cros
sth
e ro
ad f
rom
the
NE
end
of C
arve
r St
.
On
the
NW
sid
e of
the
park
ing
lot b
ehin
dth
e M
B c
onve
ntio
n/ci
vic
cent
er
50 ft
NE
of th
e N
end
of S
pive
y A
ve.
_ 4
Tim
e D
ate
,u
(hou
rs)
06/1
5/92
08/0
4/92
08/0
5/92
06/2
3/93
06/2
3/93
11/0
7/91
08/0
1/91
11/0
7/91
08/0
1/91
09/1
0/91
06/1
5/92
08/0
5/92
Feca
l col
ifor
m
(col
/lOO
mL
)
2,10
040
,000
3,00
0 15 17 770
2,50
030
0 (K
)
2,80
0 (K
)~
620
1,50
0
Feca
l st
rept
ococ
cus
Rem
arks
(c
ol/lO
Om
L)
3,80
03,
200
1,60
0 32 28 20 (K
)
2,70
026
0 (K
)
1,10
01,
200
840
1,20
0
22 23
0211
0737
4.99
5
0211
0737
5
M-2
M-2
Ope
n di
tch
on th
e SW
06
/15/
92
side
of t
he N
end
of
Spiv
ey A
ve.
200
ft do
wns
trea
m o
f 06
/15/
92
Spiv
ey A
ve.
2,20
02,
000
Stre
am w
as d
ry a
t tim
e of
sa
mpl
ing.
Tabl
e 20
.-R
esul
ts o
f bac
teria
sam
plin
g at
var
ious
loca
tions
with
in th
e W
ither
s S
was
h B
asin
and
in th
e A
tlant
ic O
cean
nea
r the
mou
th o
f With
ers
Swas
h, M
yrtle
Bea
ch,
S.C
., A
ugus
t 19
91 t
hrou
gh J
une
7993
--C
ontin
ued
[Col
/100
mL,
col
onie
s pe
r 10
0 m
illili
ters
; W, w
est;
Ave.
, ave
nue;
N, n
orth
; S, s
outh
; US,
Uni
ted
Sta
tes;
Hw
y., h
ighw
ay; X
, int
erse
ctio
n; -
-, no
dat
a;(K
), de
note
s a
non-
idea
lcou
nt;
St.,
Stre
et; f
t, fe
et;
NE,
nor
thea
st;
SE, s
outh
east
; SW
, sou
thw
est;
NW
, no
rthw
est;
<, le
ss th
an; S
C,
Sout
h C
arol
ina;
Rt.,
rou
te; e
xt.,
exte
nsio
n; E
, eas
t; R
d., r
oad;
MB,
Myr
tle B
each
; U
SGS,
U.S
. Geo
logi
cal S
urve
y; >
, gre
ater
than
; Blv
d, b
oule
vard
]
o
Iden
tifi
catio
n St
atio
n nu
mbe
r nu
mbe
r (fi
g- 4
)
24
0211
0737
6
25
0211
0737
7.96
5
26
0211
0737
7.97
5
27
0211
0737
7.98
0
28
0211
0737
7.99
0
Wat
erco
urse
M-2
Unn
amed
tr
ibut
ary
toM
-2
Unn
amed
tr
ibut
ary
to
M-2
Unn
amed
tr
ibut
ary
toM
-2
Unn
amed
tr
ibut
ary
toM
-2
Site
loc
atio
n
Ups
tream
sid
e of
10
th A
ve. N
bri
dge
On
the
SE s
ide
of O
ak
St.,
at th
e Ja
ckso
n St
./Oak
St.
X
On
the
NW
sid
e of
O
ak S
t., 5
0ft N
E o
f th
e Ja
ckso
n St
. X
300
ft N
of t
he J
ack
so
n St
./Oak
St.
X, a
nd
400
ft W
of t
he O
ak
St./
10th
Ave
. NX
.
300
ft N
W o
f L
umbe
r St.,
350
ft N
E
of C
ampb
ell
St.,
next
.
Ti
me
Dat
e (h
ours
)
08/0
1/91
09
/10/
91
06/1
5/92
08
/05/
92
11/0
6/91
11/0
6/91
11/0
6/91
06/1
5/92
Feca
l col
ifor
m
(col
/1 0
0 m
L)
1,80
0
1,50
0 1,
200
470
1,50
0
130(
K)
730
Feca
l st
rept
ococ
cus
Rem
arks
(c
ol/1
00
mL
)
760
460
2,00
0 1,
000
860
790 10
(K)
1,10
0
29
0211
0737
8.94
0M
-2
to a
sho
rt c
onne
ctin
g dr
ivew
ay b
etw
een
2 la
rge
park
ing
lots
In a
sto
rm d
rain
50
ft W
of t
he C
edar
St
./8th
Ave
. N X
06/1
5/92
2,00
02,
900
Tabl
e 20
.-R
esul
ts o
f bac
teria
sam
plin
g at
var
ious
loca
tions
with
in th
e W
ither
s S
was
h Ba
sin
and
in th
e A
tlant
ic O
cean
nea
r the
mou
th o
f With
ers
Swas
h, M
yrtle
Bea
ch,
S.C
., A
ugus
t 19
91 t
hrou
gh J
une
7995
-Con
tinue
d
[Col
/100
ml_,
col
onie
s pe
r 10
0 m
illili
ters
; W
, wes
t; Av
e., a
venu
e; N
, nor
th;
S, s
outh
; U
S, U
nite
d S
tate
s; H
wy.
, hig
hway
; X, i
nter
sect
ion;
--,
no d
ata;
(K),
deno
tes
a no
n-id
eal c
ount
; St.,
Stre
et; f
t, fe
et;
NE,
nor
thea
st;
SE,
sout
heas
t; SW
, so
uthw
est;
NW
, no
rthw
est;
<, le
ss th
an;
SC, S
outh
Car
olin
a;R
t., r
oute
; ext
., ex
tens
ion;
E, e
ast;
Rd.
, ro
ad; M
B, M
yrtle
Bea
ch;
USG
S, U
.S. G
eolo
gica
l Sur
vey;
>, g
reat
er th
an;
Blvd
, bo
ulev
ard]
Iden
tifi
catio
n St
atio
n nu
mbe
r nu
mbe
r (f
ig. 4
)
30
0211
0737
8.94
5
Wat
erco
urse
Unn
amed
tr
ibut
ary
to
M-2
.
.
Tim
e Fe
cal c
olif
orm
Si
te l
ocat
ion
Dat
e ...
....
(hou
rs)
(col
/lOO
mL
)
In a
n op
en d
itch,
on
06/1
5/92
th
e SW
sid
e of
8th
A
ve.
N, 5
0 ft
E of
Ced
ar S
t./8t
h A
ve.
NX
Feca
l st
rept
ococ
cus
(col
/1 0
0 m
L)
~
Rem
arks
Cha
nnel
was
dry
at t
ime
of
sam
plin
g.
00
31 32 33 34 35
0211
0737
8.95
0
0211
07378.960
M-2
M-2
0211
07378.970
0211
0737
8.98
0
0211
0737
8.99
0
M-2
M-2
M-2
On
theS
sid
e of
the
Ced
ar S
t./U
S H
wy.
50
1 X
100
ft N
of t
he
Bal
sam
St./
4th
Ave
. N
X, n
ear
the
foot
br
idge
in t
he p
ark
250
ft N
of t
he A
lder
St
./3rd
Ave
. N X
On
the
SW s
ide
of 3
rd
Ave
. N, 7
5 ft
NW
of
the
Ald
er S
t./3r
d A
ve.
NX
350
ft W
of t
he A
lder
St
./3rd
Ave
. N X
06/1
7/92
08/0
1/91
09
/10/
91
11/0
7/91
06
/17/
92
08/0
5/92
11/0
6/91
11
/07/
91
06/1
5/92
06
/16/
92
09/1
0/91
06
/15/
92
11/0
6/91
06
/15/
92
05/1
5/92
06
/23/
93
400
(K)
2,70
0
2,300 (K)
--
1,100(K)
200 (K)
3,000
550
130(K)
3,400
1,80
0
2,20
0
700
1,60
0860
2,10
0350 (K)
220
220 (K)
3,00
05,800
1,600
2,60
0
380
3,40
01,
500 58
400
3,70
0 4,
500
180(
K)
Tabl
e 20
.--R
esul
ts o
f bac
teria
sam
plin
g at
var
ious
loca
tions
with
in th
e W
ither
s S
was
h B
asin
and
in th
e A
tlant
ic O
cean
nea
r the
mou
th o
f With
ers
Sw
ash,
Myr
tle B
each
, S.
C.,
Aug
ust
1991
thr
ough
Jun
e 79
93--C
ontin
ued
[Col
/100
ml_,
col
onie
s pe
r 10
0 m
illili
ters
; W, w
est;
Ave.
, ave
nue;
N,
north
; S, s
outh
; U
S, U
nite
d S
tate
s; H
wy.
, hi
ghw
ay;
X, in
ters
ectio
n; -
-, no
dat
a;(K
), de
note
s a
non-
idea
l cou
nt; S
t., S
treet
; ft,
feet
; N
E, n
orth
east
; SE,
sou
thea
st; S
W, s
outh
wes
t; N
W,
north
wes
t; <,
less
than
; SC
, So
uth
Car
olin
a;R
t., r
oute
; ext
., ex
tens
ion;
E, e
ast;
Rd.
, roa
d; M
B, M
yrtle
Bea
ch;
USG
S, U
.S. G
eolo
gica
l Sur
vey;
>, g
reat
er th
an;
Blvd
, bou
leva
rd]
Iden
tifi-
, ,
Wat
erco
urse
Si
te l
ocat
ion
Dat
e nu
mbe
r nu
mbe
r(f
ig. 4
)
36
0211
0738
0 M
ains
tem
U
SGS
stag
e ga
ge a
t 08
/01/
91B
ranc
h th
e br
idge
on
Bro
ad-
09/1
0/91
way
St.
(Old
Con
way
09
/ 1 9
/9 1
Hw
y.),
200
ft W
of
09/2
0/91
the
Col
lins
St. X
09
/20/
9109
/20/
9109
/24/
9109
/24/
9109
/24/
9106
/04/
9206
/15/
9207
/18/
9207
/19/
9207
/20/
9207
/20/
9207
/20/
9207
/20/
9208
/03/
9208
/03/
9208
/03/
9208
/04/
9208
/05/
9206
/22/
9306
/22/
93
37
0211
0738
4.98
0 K
OA
Bra
nch
500
ft N
of t
he X
of
08/0
1/91
Bea
ver
Rd.
and
17t
h 09
/10/
91A
ve. S
, 200
ft N
E of
11
/08/
9117
th A
ve. S
Tim
e (h
ours
)
- 1310
0300
0330
0700
1330
1635
1655 - ~ 1845
1430
1720
1725
1745
1835
1412
1535
2100 - ~ -- - «
Feca
l col
ifor
m
(col
/lOO
mL
)
2,50
0 -1,
400
220,
000
640,
000
800,
000
3,80
092
,000
1,50
0,00
010
,000
2,70
06,
000
59,0
005,
300
(K)
5,00
0 (K
)64
,000
,000
(K)
27,0
00,0
00 (K
)55
,000
38,0
0031
,000
13,0
002,
000 32 30
1,50
0(K
)
<17
Feca
l st
rept
ococ
cus
(col
/1 0
0 m
L)
1,30
01,
800
100(
K)
600
(K)
4,40
055
0 (K
)2,
400
71,0
0016
5,00
0 --3,
500
1 4,0
00 (K
)15
,000 300
300
660,
000
1 90,
000
(K)
88,0
0058
,000
35,0
0056
,000
1,40
0 36 30 100(
K)
1,80
0<2
0
Rem
arks
« - - - - - - - -- ~ - - - - ~ ~ ~ -
Tabl
e 2Q
.~R
esul
ts o
f bac
teria
sam
plin
g at
var
ious
loca
tions
with
in th
e W
ither
s S
was
h B
asin
and
in th
e A
tlant
ic O
cean
nea
r the
mou
th o
f With
ers
Swas
h, M
yrtle
Bea
ch,
S.C
., A
ugus
t 19
91 t
hrou
gh J
une
7993
--Con
tinue
d
[Col
/100
ml_,
col
onie
s pe
r 10
0 m
illilit
ers;
W, w
est;
Ave.
, ave
nue;
N, n
orth
; S,
sou
th; U
S, U
nite
d S
tate
s; H
wy.
, hig
hway
; X, i
nter
sect
ion;
--,
no d
ata;
(K),
deno
tes
a no
n-id
eal c
ount
; St.,
Stre
et; f
t, fe
et;
NE,
nor
thea
st; S
E, s
outh
east
; SW
, sou
thw
est;
NW
, nor
thw
est;
<, le
ss th
an; S
C, S
outh
Car
olin
a;R
t., r
oute
; ext
., ex
tens
ion;
E, e
ast;
Rd.
, ro
ad;
MB,
Myr
tle B
each
; U
SG
S,
U.S
. G
eolo
gica
l Sur
vey;
>, g
reat
er th
an;
Blvd
, bou
leva
rd]
Iden
tifi
ca
tion
num
ber
(fig-
4)
38 39
Stat
ion
num
ber
0211
0738
4.98
5
0211
0738
4.99
0
Wat
erco
urse
Si
te lo
catio
n
KO
A B
ranc
h O
n 1 3
th A
ve.
S,
400
ft N
W o
f the
Bea
ver R
d. X
KO
A B
ranc
h O
n 1 1
th A
ve.
S,1,
200
ft N
W o
f the
Tim
e D
ate
(hou
rs)
11/0
8/91
08/0
1/91
06/2
3/93
Feca
l col
ifon
n (c
ol/1
00
mL
)
200
(K)
1,10
0 44
Feca
l st
rept
ococ
cus
(col
/1 0
0 m
L)
40 (K
)
<20 47
Rem
arks
- _ --
40 41
0211
0738
4.99
5
0211
0738
5
Unn
amed
tr
ibut
ary
to
KO
A B
ranc
h
KO
A B
ranc
h
Oak
St.
X, a
nd 4
00 f
t fr
om th
e en
d of
11 t
h A
ve.
S
500f
tNW
ofth
eNW
en
d of
Tal
bot C
ircl
e
USG
S st
age
gage
20
0ftS
Wof
theN
W
end
of T
albo
t Cir
cle
08/0
1/91
3,90
0<2
0
08/0
1/91
09/1
0/91
09/1
9/91
09/2
0/91
09/2
0/91
09/2
0/91
09/2
4/91
09/2
4/91
09/2
4/91
09/2
4/91
11/0
8/91
06/0
4/92
07/1
8/92
07/1
9/92
07/2
0/92
07/2
0/02
07/2
0/92
08/0
3/92
08/0
3/92
08/0
3/92
06/2
3/93
~ - 1315
0305
0345
0700
1330
1640
1715
1805 ~ 1830
1445
1805
1340
1930
1430
1610
2035 --
3,00
0 -1,
200
21,0
0019
,000
12,0
001,
900
45,0
0010
0,00
027
,000
1,60
02,
800
5,50
06,
900 60
(K)
250
(X)
1,20
012
,000
58,0
0025
,000 ~
<20
2,30
0 (K
)<5
0<5
0 50 (K
)<5
02,
400
37,0
0050
,000
28,0
001,
000
> 10
,000
13,0
004,
400
70,0
001,
000
200,
000
130,
000
120,
000
124(
K)
Tabl
e 20
.--R
esul
ts o
f bac
teria
sam
plin
g at
var
ious
loca
tions
with
in th
e W
ither
s S
was
h B
asin
and
in th
e A
tlant
ic O
cean
nea
r the
mou
th o
f With
ers
Swas
h, M
yrtle
Bea
ch,
S.C
., A
ugus
t 19
91 t
hrou
gh J
une
7993
--C
ontin
ued
[Col
/100
ml,
colo
nies
per
100
mill
ilite
rs; W
, wes
t; Av
e., a
venu
e; N
, nor
th; S
, sou
th;
US,
Uni
ted
Sta
tes;
Hw
y., h
ighw
ay; X
, int
erse
ctio
n; -
-, no
dat
a;(K
), de
note
s a
non-
idea
l cou
nt; S
t., S
treet
; ft,
feet
; N
E, n
orth
east
; SE,
sou
thea
st; S
W, s
outh
wes
t; N
W,
north
wes
t; <,
less
than
; SC
, So
uth
Car
olin
a;R
t., r
oute
; ext
., ex
tens
ion;
E, e
ast;
Rd.
, roa
d; M
B, M
yrtle
Bea
ch; U
SGS,
U.S
. Geo
logi
cal S
urve
y; >
, gre
ater
than
; Bl
vd.
boul
evar
d]
Iden
tifi
catio
n St
atio
n nu
mbe
r nu
mbe
r (fi
g- 4
)
42
0211
0738
5.01
0
43
0211
0738
5.02
0
44
0211
0738
5.03
0
Wat
erco
urse
Si
te lo
catio
n
KO
A B
ranc
h A
t the
NW
end
of
1 Oth
Ave
. S (
Roa
d en
ds h
ere)
KO
A B
ranc
h A
t 9th
Ave
. S, 4
00 f
t N
W o
f the
Oak
St.
X
KO
A B
ranc
h A
t the
bri
dge
1 00
ft SE
of t
he X
of 5
thA
ve. S
and
Bou
ndar
y St
.
_ _
Tim
e D
ate
(hou
rs)
__
«
11/0
8/91
08/0
1/91
09
/10/
9111
/08/
91
06/2
3/93
Feca
l col
ifor
m
(col
/100
mL
)
"
3,00
0
3,30
0
320
(K)
42
Feca
l st
rept
ococ
cus
(col
/1 0
0 m
L)
~~
1,80
0
<20
170 40 (K
) 33
Rem
arks
Stre
am w
as d
ry a
t tim
e of
sa
mpl
ing.
-- --
4502
1107
385.
040
Tid
al b
asin
4602
1107
388
With
ers
Swas
h
On
the
W s
ide
of th
e m
ain
pool
of t
he ti
dal
basi
n, 9
00 f
t NW
of
US
Hw
y. 1
7 (B
usi
ne
ss),
and
300
ft N
E
of 5
th A
ve. S
USG
S st
age
gage
, up
stre
am s
ide
of th
e cu
lver
t, 30
0 ft
SW o
f th
e X
of U
S H
wy.
17
(Bus
ines
s) a
nd 3
rd
Ave
. S
06/1
7/92
2,00
018
0(K
)
09/1
9/91
09/2
0/91
09/2
4/91
09/2
4/91
09/2
4/91
06/0
4/92
06/1
5/92
06/1
6/92
08/0
5/92
06/2
3/93
1305
1025
1315
2104
2154
1610 - -- ~
<50
150,
000 63 (K
)14
,000
7,20
014
,000
1,90
02,
300
3,00
0 24
<50 50
(K)
9614
,000
13,0
00 -50
0 (K
)44
0 (K
)12
,000 1
O fV
\1
0 «
xO
Tabl
e 20
.- R
esul
ts o
f bac
teria
sam
plin
g at
var
ious
loca
tions
with
in th
e W
ither
s S
was
h B
asin
and
in th
e A
tlant
ic O
cean
nea
r the
mou
th o
f With
ers
Swas
h, M
yrtle
Bea
ch,
S.C
., A
ugus
t 19
91 t
hrou
gh J
une
7993
-Con
tinue
d
[Col
/100
ml,
colo
nies
per
100
mill
ilite
rs;
W, w
est;
Ave
., av
enue
; N
, no
rth;
S, s
outh
; U
S,
Uni
ted
Sta
tes;
Hw
y.,
high
way
; X,
inte
rsec
tion;
--,
no d
ata;
(K),
deno
tes
a no
n-id
eal c
ount
; S
t., S
treet
; ft,
feet
; N
E,
north
east
; S
E,
sout
heas
t; SW
, so
uthw
est;
NW
, no
rthw
est;
<, le
ss th
an;
SC
, S
outh
Car
olin
a;R
t., r
oute
; ex
t., e
xten
sion
; E,
eas
t; R
d.,
road
; M
B,
Myr
tle B
each
; U
SG
S,
U.S
. Geo
logi
cal S
urve
y; >
, gre
ater
than
; B
lvd,
bou
leva
rd]
ro
Iden
tifi
catio
n St
atio
n nu
mbe
r nu
mbe
r (f
ig. 4
)
47
0211
0738
8.01
0
48
0211
0738
8.02
0
49
0211
0738
8.03
0
Wat
erco
urse
Atla
ntic
O
cean
Atla
ntic
O
cean
Atla
ntic
O
cean
Site
loca
tion
In th
e su
rf, 7
0 -1
00 f
t N
E of
cen
ter
of
With
ers
Swas
h co
n
flue
nce
with
oce
an
In th
e su
rf, c
ente
r of
W
ither
s Sw
ash
con
fl
uenc
e w
ith o
cean
In th
e su
rf, 7
0 -
100f
t S W
of c
ente
r of
_. _
Tim
e D
ate
,, ,
(hou
rs)
06/0
4/92
08
/05/
92
06/0
4/92
08
/05/
92
08/0
5/92
Feca
l col
ifor
m
(col
/ 100
mL
)
49 (K
) 70
0 (K
)
15,0
00
2,20
0
<50
Feca
l st
rept
ococ
cus
(col
/1 0
0 m
L)
50 (K
)
50 (K
)
<50
Rem
arks
- -- -
50
0211
0740
0.01
0St
orm
dra
in
With
ers
Swas
h co
n
flue
nce
with
oce
an
In a
str
eet d
rain
con
fl
uenc
e on
the
SE s
ide
of N
Oce
an B
lvd.
, in
fron
t of
And
erso
n In
n, b
etw
een
26th
and
27
th A
ve. N
06/0
4/92
570
51
0211
0740
0.02
0 St
orm
di
scha
rge
culv
ert
On
the
beac
h, 1
90ft
06
/04/
92
--
31(K
) SE
of t
he m
iddl
e co
rrug
ated
met
al
pipe
out
fall
for
stor
m
disc
harg
e be
hind
A
nder
son
Inn,
300
ft
SE o
f site
02
1107
400.
010
APPENDIX 1
Results of physical property, oxygen demand, total organic carbon, total residue, turbidity, hardness, major ion, and alkalinity analyses of water samples collected at three gaging stations in the Withers Swash Basin, Myrtle Beach, S.C, September 1991 through August 1992
73
Appe
ndix
1.
--Re
sult
s of ph
ysic
al pr
oper
ty,
oxygen de
mand
, total
orga
nic
carb
on,
total
residue, turbidit
y, hardness,
major
ion, an
d alkalinity analyses of water
samples
collected
at three ga
ging
st
atio
ns in the
Withers
Swas
h Basin, My
rtle
Be
ach,
S.C.,
September
1991
th
roug
h August 1992
[ft3/
s, cubic
feet
per
seco
nd;
°C,
degr
ees
Celsius,-
lab,
la
bora
tory
,- fiS/cm,
microsiemens per
cent
imet
er at 25 °C;
mg/L
, milligrams per
liter,-
NTU,
ne
phel
omet
ric
turbidity
unit
s; --,
no data
,- <, le
ss than]
Stat
ion
number
0211
0738
0(Mainstem)
021107385
(KOA
)
021107388
(Swash)
Date
09-20-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
07-20-92
07-20-92
07-20-92
08-03-92
08-03-92
08-03-92
09-20-91
09-24-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
07-20-92
07-20-92
08-03-92
08-03-92
08-03-92
09-24-91
09-24-91
09-24-91
Time
(hou
rs)
0300
1330
1635
1655
1845
1720
1725
1745
1835
1412
1538
2100
0305
1330
1640
1715
1805
1830
1805
1840
1930
1430
1610
2035
1315
2104
2154
Discharge,
instantaneous
(ft3/
s)
1(00061)
1.1
0.60
17 11
0.60
1.3
1.8
2.4
1.5
10 65 6.2
2.1
1.5
5.2
5.3
3.2
1.6
2.1
2.5
2.2
17 71 6.7
-- -- --
Temperature
, water
(°C)
1(00010)
24.0
23.0
26.0
26.0
25.0
24.5
24.5
24.5
26.0
28.0
25.5
26.0
25.0
23.5
25.0
25.0
25.0
25.0
26.5
26.0
26.5
27.0
25.5
25.5
27.0
25.0
25.0
pH,
Water
whol
e,
lab
(pH
unit
s)
1(00403)
7.4
7.5
7.7
7.5
7.6
7.5
7.4
7.3
7.3
8.1
7.7
7.2
7.3
7.3
7.2
7.4
7.3
7.6
10.4
6.8
3.2
6.6
7.2
7.8
7.7
7.9
7.7
Specific
cond
ucta
nce
(MS/
cm)
1(00095)
510
624
235
206
320
627
629
566
450
103 88
127
335
350
245
150
140
380
1,000
1,000
1,200
317 82
145
46,200
47,000
46,000
Specific
conductance,
lab
(/iS/cm)
1(90095)
538
657
234
278
601
590
549
425
444
103 98
133
333
336
183
133
132
369
968
986
1,200
327 87
150
45,200
38,000
36,600
Oxyg
en,
dissolved
(mg/L)
1{0
0300
)3.5
3.5
6.0
5.7
3.9
4.5
4.5
4.4
4.2
5.8
5.2
4.8
2.6
3.4
4.3
4.4
4.4
3.8
4.2
4.1
4.5
5.3
5.1
4.9
7.6
5.9
6.2
Oxygen,
dissolved
(percent
saturation)
1(00301)
41
41 74 70
47 54 54 52 51
74 64 59 31
40
52 53 53 46 52 51 56 67 62 60
113 85 89
Appendix
] --Results
of physical property,
oxyg
en de
mand
, to
tal
orga
nic
carb
on,
total
residue, turbidity, hardness,
majo
r ion, an
d al
kali
nity
analyses of wa
ter
samples
coll
ecte
d at
three
gaging stations in
the
Withers
Swash
Basi
n, My
rtle
Be
ach,
S.C.,
September
1991
th
roug
h Au
gust
1992--Continued
[ft
/s,
cubi
c feet per
seco
nd;
°C,
degrees
Celsius; la
b, laboratory;
/zS/cm,
microsiemens per
cent
imet
er at 25
°C;
mg/L
, milligrams per
lite
r; NTU, nephelometric
turbidity
unit
s; --,
no da
ta,-
<, less than]
cn
Station
number
021107380
(Mainstem)
0211
0738
5(K
OA)
021107388
(Swa
sh)
Date
09-20
09-24
09-24
09-24
07-18
07-20
07-20
07-20
07-20
08-03
08-03
08-03
09-20
09-24
09-24
09-24
09-24
07-18
07-20
07 20
07-20
08-03
08-03
08-03
09-24
09-24
09-24
-91
-91
-91
-91
-92
-92
-92
-92
-92
-92
-92
92
-91
-91
-91
-91
-91
-92
-92
-92
-92
-92
-92
-92
-91
-91
-91
Time
(hours)
0300
1330
1635
1655
1845
1720
1725
1745
1835
1412
1538
2100
0305
1330
1640
1715
1805
1830
1805
1840
1930
1430
1610
2035
1315
2104
2154
Oxygen
dema
nd,
bioc
hemi
cal,
5 day
(mg/L)
1(00310)
12 6.5
10 12'
--
7.0
7.0
-- -- 21 17 15
9.0
6.0
7.5
13
9.5
--
7.5
-- -- 24 17 13
6.0
12
7.0
Oxygen
demand ,
chemical
(high level)
(mg/
L)
1(0
0340
)
86 27 80 99 27 -- 30 85 28 46'
15 29 67 32
120 62 41 59
110
43 87 77 23 43 810
730
620
Carbon ,
organic,
total
(mg/L)
1(0
0680
)-- -- -- -- 11 16 22 42 25 18 10 11 -- -- -- -- 19 50 13 32 25 15 18 -- -- --
Resi
due
at 105
°C,
dissolved
(mg/L)
1(00515)
353
399 97
161
-- -- -- -- -- -- -- -- 195
213
129 90 90
_- -- -- -- _- -- --
34,700
29,900
28,100
Resi
due
at 105
°C,
suspended
(mg/L)
1(00530)
17 <1 59 30 16 22
22
40 30
231 77 28 18
1
97
168
47 36 54 36 28
126
101 28
2 8
14
Solids,
residue
at 180 °C,
dissolved
Turbidity
(mg/
L)
(NTU)
1(70300)
1(00076)
5.5
24 67 55
358
370
363
322
281 78 68
108
3.0
3.0
37 60
7.0
218
568
541
640
222 73
123
2.2
8.4
10
Hard
ness
, total
(mg/L
as
CaC0
3)
1(00900)
-- -- -- --
210
220
220
170
160 35 36 56 __ -- -- -- -- 79 50 240
240 67 28 49 _- -- --
Appe
ndix
1.
--Re
sult
s of physical pr
oper
ty,
oxygen demand,
total
orga
nic
carb
on,
tota
l residue, turbidit
y, ha
rdne
ss,
major
ion,
an
d al
kali
nity
analyses of water
samples
collected
at three
gaging stations in the
With
ers
Swas
h Basin,
My
rtle
Be
ach,
S.C.,
Sept
embe
r 19
91 through
Augu
st 19
92--Continued
[ft
/s,
cubic
feet per
seco
nd;
°C,
degr
ees
Celsius; la
b, la
bora
tory
,- /xS/cm,
micr
osie
mens
per
cent
imet
er at 25
°C;
mg/L,
milligrams per
liter,-
NTU, nephelometric
turbidity
units,-
--,
no da
ta,- <, less than]
O
Station
number
021107380
(Mainstem)
021107385
(KOA
)
021107388
(Swa
sh)
Date
09-20-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
07-20-92
07-20-92
07-20-92
08-03-92
08-03-92
08-03-92
09-20-91
09-24-91
09-24-91
09-24- 91
09-24-91
07-18-92
07-20-92
07-20-92
07-20-92
08-03-92
08-03-92
08-03-92
09-24-91
09-24-91
09-24-91
Time
(hours)
0300
1330
1635
1655
1845
1720
1725
1745
1835
1412
1538
2100
0305
1330
1640
1715
1805
1830
1805
1840
1930
1430
1610
2035
1315
2104
2154
Alkalinity,
lab
(mg/
L as
CaC0
3)
1(90410)
208
272
96
114
235
222
203
146
159
53 37 46 91 95 51 36 40 99
232 19 <1.0
46 28 39
129
117
116
Calcium,
dissolved
(mg/L)
1(00915)
-- -- 79 83 83 65 58 13 13 20 -- -- -- -- -- 29 19 85 88 24 10 17 -- --
Magnesium,
diss
olve
d (m
g/L)
1(00925)
3 3 3 2 2 0 0 1 1 0 6 5 1 0 1
-- -- .2 .4 .4 .9 .6 .68
.76
.5 -_ -- -- -- -- .7 .72
. 1 .6 .7 .80
.7 -- --
Sodi
um,
dissolved
(mg/L)
1(00930)
-- -- 48 50 49
40 31
4.6
4.0
5.7
-- -- -- -- -- 44
180 34 58 31
4.5
9.8
-- --
Potassiu
m,
dissolved
(mg/L)
1(00935)
- - 3 4 3 2 2 1 1 1 - - - - - 2 2 4 4 2 2 3 - - -
- - .0 .1 .1 .9 .6 .1 .3 .8 - - - - - .4 .7 .3 .4 .7 .1 .8 - - -
Chloride,
dissolved
(mg/
L)
1(0
0940
)
-- -- 42
45
45 39 32
4.4
4.2
21 -- -- -- -- -- 32
150
220
270 68
4.7
9.8
-- -- --
Solids,
sum
of
Sulfate,
cons
titu
ents
, di
ssol
ved
diss
olve
d
(mg/
L)
(mg/L)
1(0
0945
) 1(70301)
-- -- 32 34 34 33 25
9.1
8.2
12 -- -- -- -- -- 35 53 35 33 23
7.6
15 -- -- --
-- --
348
353
339
270
247 65 54 90 -- -- -- -- --
203
545
396 --
178
46 80 -- -- --
Parameter
code
, National Water
Data
Storage
and
Retrieval
System of the
U.S.
Ge
olog
ical
Su
rvey
.
APPENDIX 2
Results of nutrient analyses of water samples collected at three gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992
77
Appe
ndix
/
Results
of nutrient analyses of wa
ter
samples
coll
ecte
d at three
gaging stations in the
With
ers
Swash
Basi
n, My
rtle
Be
ach,
S
0 , Se
ptem
ber
1991
th
roug
h Au
gust
1992
o[ft
/s,
cubic
feet per
seco
nd;
mg/L
, mi
llig
rams
per
lite
r,-
<, less th
an;
--,
no da
ta]
Oo
Stdt
i on
Date
numb
er
021107380
09-20-
(Mainstem)
09-
09-
09-
24-
24-
24-
07-18-
07-
07-
07-
07-
08-
08-
08-
021107385
09-
(KOA
) 09-
09-
09-
09-
07-
07
07-
07-
08 08-
08-
021107388
09-
(Swa
sh)
09-
09-
20-
20-
20-
20-
03-
03-
03-
20-
24-
24-
24-
24-
18-
20-
20-
20-
03-
03-
03
24 24-
24
91 91 91 91 92 92 92 92 92 92 92 92 91 91 91 91 91 92 92 92 92 92 92 92 91 91 91
Time
(hours)
0300
1330
1635
1655
1845
1720
1725
1745
1835
1412
1538
2100
0305
1330
1640
1715
1805
1830
1805
1840
1930
1430
1610
2035
1315
2104
2154
Discharge,
intantaneous
(ft3/
s)
1(0
0061
)1.1 .60
17 11
.60
1.3
1.8
2.4
1.5
10 65
6.2
2.1
1.5
5.2
5.3
3.2
1.6
2.1
2.5
2.2
17 71
6.7
-- -- --
Nitrogen,
total
(mg/
L)
1(00600)
1.5 .67
.72
.98
.83
1.2 .96
3.3
1.7
2.0
1.1 .93
1.8
1.2
1.7
1.5 .75
2.8
2.8
7.1
3.1
2.8
1.2
1.4
-- -- --
Nitrogen,
organi c ,
total
(mg/L)
1(0
0605
)1.1 .44
.55
.75
.26
.44
.32
1.2 .78
1.4 .53
.59
1.0 .34
.92
.97
.45
1.4 .80
3.1 .90
1.8 .73
.83
.33
.35
.34
Nitrogen,
ammonia,
total
(mg/
L)
1(00610)
0.070
.160
.050
.050
.240
.260
.280
.220
.220
.110
.070
.010
.670
.660
.580
.330
.150
1.10
1.60
.850
1.40
.280
.070
.070
.070
.050
.050
Nitrogen
nitrite,
total
(mg/
L)
1(0
0615
)
0.030
.010
.020
.010
.080
.100
.100
.090
.100
.020
.020
.020
.010
.040
.030
.020
.010
.050
.030
.070
.020
.030
.020
.030
<.010
<.010
.010
Nitrogen
nitrate,
total
(mg/L)
1(00620)
0.270
.06
.100
.170
.250
.370
.260
1.81
.590
.520
.510
.310
.054
.170
.200
.200
.140
.230
.410
.13
.730
.670
.400
.520
__ -- --
results of
nutrient analyses of water samples collected at
three gaging stations in the Withers Swash Basin, Myrtle Be
ach,
Sepi r-mber
1991 through August 1992--Continued
Q
[ft
/s,
cubic feet
per se
cond
; mg/L,
milligrams per li
ter;
<,
le
ss than;
--,
no da
ta]
Station
Date
numb
er
021107<80
09-20
(Mainstem)
09-24
09-24
09-24
07-18
07-20
07-20
07-20
07-20
08-03
08-03
08-03
02J 107385
09-20
iKOA)
09-24
09-24
09-24
09-24
07-18
07-20
07-20
07 20
08-03
08-03
08-03
021107388
09-24
(Swash)
09-24
09-24
-91
-91
-91
-91
-92
-92
-92
-92
-92
-92
-92
-92
-91
-91
-91 91
-91
-92
-92
-92
-92
-92
-92
-92
-91
-91
-91
Time
(hou
rs)
0300
1330
1635
1655
1845
1720
1725
1745
1835
1412
1538
2100
0305
1330
1640
1715
1805
1830
1805
1840
1930
1430
1610
2035
1315
2104
2154
Nitrogen,
amonia +
organic,
total
(mg/
L)'
1(00625)
1.2 .60
.60
.80
.50
.70
.60
1.4
1.0
1.5 .60
.60
1.7
1.0
1.5
1.3 .60
2.5
2.4
3.9
2.3
2.1 .80
.90
.40
.40
.40
Nitrogen,
N02+N03
,
total
(mg/
L)
1(00630)
0.300
. 074
.120
.180
.330
.470
.360
1.90
.690
.540
.530
.330
.064
.210
.230
.220
.150
.280
.440
3.20
.750
.700
.420
.550
<.050
<.050
<.050
Nitrogen,
ammonia,
total
(mg/
L)
1(71845)
0.09
.21
.06
.06
.31
.33
.36
.28
.28
.14
.09
.01
.86
.85
.75
.42
.19
1.4
2.1
1.1
1.8 .36
.09
.09
.09
.OS
.08
Phosphorus ,
total
(mg/
L)
1(0
0665
)
0.28
0
.200
1.30 .840
.190
.220
.190
.370
.230
.640
-.260
.210
.160
.120
.400
.360
.130
.860
.120
1.70 .590
.710
.290
.280
.070
.090
.090
Phosphorus ,
orth
o,
Phosphate,
total
total
(mg/L)
(mg/L)
1(7
0507
) 1(00650)
0.14
0 0.
43
.140
.4
3
.170
.5
2
.110
.34
-- __ .- _- -- _- _. -- .070
.21
.070
.2
1
.070
.21
.050
.15
.060
.18
-_ -_ .. -- __ .- -- .050
.15
.040
.12
.040
.1
2
Parameter co
de,
National Water Data Storage and Retrieval System of the U.S. Geological Survey.
APPENDIX 3
Results of trace element and cyanide analyses of water samples collected at three gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992
80
Appendix
3 Results of metal and trace element analyses of water samples collected at
three gaging stations in
the Withers Swash Ba
sin,
Myrtle
Beach,
S C.
, September 1991 through August 19
92
[ft
/s,
cubic feet per second; /xg/L, micrograms per liter;
<, less th
an;
mg/L
, milligrams per liter,-
--,
no da
ta]
Station
number
021107380
(Mains
tem)
021107385
(KOA
)
021107388
(Swa
sh)
09 09 09 09 07 07 07 07 07 08 08 08 09 09 09 09 09 07 07 07 07 08 08 08 09 09 09
Date
-20-
-24-
-24-
-24-
-18-
-20-
-20-
-20-
-20-
-03-
-03-
-03-
-20
-24
-24
-24 24 -18- 20-
-20-
-20
-03
-03-
-03-
-24-
-24-
-24-
91 91 91 91 92 92 92 92 92 92 92 92 91 91 91 91 91 92 92 92 92 92 92 92 91 91 91
Time
(hours)
0300
1330
1635
1655
1845
1720
1725
1745
1835
1412
1538
2100
0305
1330
1640
1715
1805
1830
1805
1840
1930
1430
1610
2035
1315
2104
2154
Discharge,
instantaneous
(ft3/s)
1(0
0061
)
1.
17 11
1. 1. 2. 1.
10 65
6. 2. 1. 5. 5. 3. 1. 2. 2. 2.
17 71
6. -- --
1 60 60 3 8 4 5 2 1 5 2 3 2 6 1 5 2 7
Beryllium,
Cadm
ium,
Chro
mium
,
Antimony,
Arsenic,
total
total
tota
l
total
total
recoverable
recoverable
recoverable
(jj-
g/L)
(f
ig/L
) (fjig/L)
(fig/L
) (/
xg/L
)
1(0
1097
) 1(0
1002
) 1(0
1012
) 1(0
1027)
1(0
1034
)
<1
2 <10
<1
1 <10
2 6
<10
1 4
<10
<1
<10
1 <10
<1
<10
3 <10
2 <10
2 <10
2 <10
4 <10
<1
1 <10
<1
<1
<10
2 3
<10
2 2
<10
2 1
<10
3 <10
7 <10
<1
<10
4 <10
6 <10
4 <10
4 <1
0
<1
2 <10
<1
2 <10
<1
3 <10
<1
4
<1
1
2 27
<1
13
<1
<1
<1
1
<1
<1
<1
1
<1
<1
<1
' 11
<1
2
<1
<1
<1
<1
<1
<1
2 5
3 9
<1
<1
<1
<1
2 1
7 1
7 6
2 9
<1
2
<1
<1
<10
4
<10
<4
<10
<4
Copper ,
total
recoverable
1(0
1042
)
10 2
51 16
1 2
13 12
9
19
7 6 3 4
25 30 14 22 54 44 62 43
5 4 1 3
<10
Appe
ndix
3.- -R
esul
ts of metal
and
trace
elem
ent
analyses of water
samp
les
collected
at three
gaging stations in the
With
ers
Swash
Basin, Myrtle
Beach, SO., September
1991
through August 1992--Continued
[ft
/s,
cubic
feet per se
cond
; ^g/L,
micr
ogra
ms per
lite
r;
<, less th
an;
mg/L
, milligrams pe
r li
ter;
--,
no data]
Station
numb
er
021107380
(Mai
nstem)
021107385
(KOA)
021107388
(Swash)
Date
09-2
0-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
07-20-92
07-20-92
07-20-92
08-03-92
08-03-92
08-03-92
09-20-91
09-24-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
07-20-92
07-20-92
08-03-92
08-0
3 92
08-03-92
09-24-91
09- 24
-91
09-24-91
Time
(hours)
0300
1330
1635
1655
1845
1720
1725
1745
1835
1412
1538
2100
0305
1330
1640
1715
1805
1830
1805
1840
1930
1430
1610
2035
1315
2104
2154
Cyanide,
total
(mg/
L)
1(0
0720
)
<0.010
< .0
10
< .0
10
< .010
< .0
10
< .0
10
< .0
10
< .010
< .0
10
< .0
10
< .0
10
< .0
10
< .0
10
< .010
< .010
< .0
10
< .010
< .0
10
< .010
< .0
10
< .0
10
--
< .0
10
< .0
10
< .010
< .0
10
< .0
10
Lead,
total
reco
vera
ble
1(0
1051
)9 2
140 45 <1 1 1
15 8
69 16
9 4 6
170
290 35 48
240
250
450
240 11
6
<10
<10
<10
Merc
ury,
to
tal
recoverable
(Mg/
L)
1(71900)
0.10 .20
.30
.20
.20
.40
.20
.20
.10
.50
.40
< .10
.10
.10
.10
.10
.10
.10
.30
.20
.20
.30
.30
< .10
.10
.10
.20
Nick
el,
total
recoverable
1(01067)
1 <1 8 3
<1 <1 <1 4 2 5 1 1 2 5
14 14 4 4 2
65 64 15
2 1
<1 <1
1
Silv
er,
Zinc,
Selenium,
total
tota
l total
recoverable
recoverable
(Mg/
L)
(Mg/L)
(Mg/
L)1(0
1147)
1(0
1077
) 1(01092)
<1
<1
80
<1
<1
20
<1
<1
310
<1
<1
120
<2
<1
10
<2
<1
20
<2
<1
30
<2
<1
80
<2
<1
60
<1
<1
190
<1
<1
60
<1
<1
40
<1
<1
30
<1
<1
20
<1
28
180
<1
30
250
<1
7 40
<2
4 110
<2
14
490
<2
1 2,300
<2
1 1,
600
<1
45
300
<1
2 40
<1
<1
30
<1
<1
<10
<1
<1
20
<1
<1
30
Para
mete
r code,
Nati
onal
Water
Data
St
orag
e and
Retrieval
System of the
U.S. Geological Survey.
APPENDIX 4
Results of volatile organic compound analyses of water samples collected at three gaging stations in the Withers Swash Basin, Myrtle Beach, S.C, September 1991 through August 1992
83
Oo
Appendix 4.
--Re
sult
s of
volatile organic
compound an
alys
es of water
samples
collected
at three
gaging st
atio
ns in th
e Withers
Swash
Basi
n, Myrtle Beach,
S.C.
, Se
ptem
ber
1991 th
roug
h August 1992
o
[All concentrations in micrograms per liter except where indicated; ft
/s
, cubic feet per second; rec,
recovered; <, less than,- --
, no da
ta]
Station
number
021107380
(Mainstem)
021107385
(KOA
)
021107388
(Swash)
Date
09-20-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
07-20-92
08-03-92
09-20-91
09-24-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
08-03-92
09-24-91
09-24-91
09-24-91
Discharge,
1, 1, 1,
2-Tetra-
1,1,1-Tri-
Time
instantaneous
chloroethane,
chloroethane,
(hou
rs)
(ft3/
s)
tota
l rec
total
1(0
0061
) 1(7
7562
) 1(34506)
0300
1.1
1330
.60
1635
17
1655
11
1845
.60
<0.2
1720
1.3
< .2
1725
1.8
< .2
1412
10
< .2
0305
2.1
1330
1.5
1640
5.2
1715
5.3
1805
3.2
1830
1.6
< .2
1840
2.5
< .2
1430
17
< .2
1315
2104
2154
<0.2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
44 55
230
150
120 27 27
350
.2
< .2 .6
1, 1,2,2-Tetra-
1,1,2-Tri-
chloroethane ,
chloroethane ,
total rec
total
1(3
4516
) 1(3
4511
)
<0.2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
<0.2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
1,1-
Di-
chloroethane,
total
1(34496)
<0.2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
4.3
4.2
2.7
1.8
1.2
2.9
3.5
2.1
< .2
< .2
< .2
1, 1-Dichloro-
1, 1-D
ichl
oro-
et
hyle
ne,
prop
ene,
total
total
1(3
4501
) 1(77168)
<0.2
< .2
< .2
< .2
< .2
< .2
< .2
< .2 .6 .9
3.4
2.5
1.8
2.4
2.9
26 < .2
< .2
< .2
-- -- --
<0.2
< .2
< .2
< .2 -- -- -- --
< .2
< .2
< .2 -- --
Appendix 4.
Results
of volatile organic
compound analyses of water
samp
les
collected
at three
gaging stations in th
e Withers
Swash
Basi
n, Myrtle Beach,
S.C
, Septem
ber
1991 through August 19
92--
Cont
inue
d
[All
co
ncen
trat
ions
in micrograms pe
r liter
except wh
ere
indicated; ft /s,
cubi
c feet pe
r second;
rec, recovered; <, le
ss than,- --,
no data]
OD
Station
number
021107380
(Mainstem)
021107385
(KOA)
Date
09-20
09-24
09-24
09-24
07-18
07-20
07-20
08-03
09-20
09-24
09-24
09-24
09-24
-91
-91
-91
-91
-92
-92
-92
-92
-91
-91
-91
-91
-91
07-18-92
021107388
(Swash)
07-20
08-03
09-24
09*24
09-24
-92
-92
-91
-91
-91
1,2,3-Tri-
1,2,3-Tri-
Time
chlorobenzene, chloropropane,
(hours)
total rec
total
1(7
7613
) 1(77443)
0300
1330
1635
1655
1845
<0.20
<0.2
1720
< .20
< .2
1725
< .2
0 <
.2
1412
< .20
< .2
0305
1330
1640
1715
1805
1830
< .20
< .2
1840
< .20
< .2
1430
< .20
< .2
1315
2104
2154
1,2,4-Tri-
chlorobenzene ,
total rec
1(34551)
<5.0
<5.0
<5.0
<5.0
< .20
< .20
< .20
< .2
0
<5.0
<5.0
<5.0
<5.0
<5.0
< .20
< .20
< .20
<5.0
<5.0
<5.0
Pseudocumene, o-Chloro-
1,2-Di-
water,
toluene, bromoethane
total rec
total
total
1(77222)
1(77275)
1(77651)
<0.2
< .2
< .2
< .2
<0.20
<0.2
< .2
< .20
< .2
< .2
< .20
< .2
< .2
< .20
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .20
< .2
< .2
< .20
< .2
< .2
< .20
< .2
< .2
< .2
< .2
< .2
o-Chloro-
, benzene ,
total rec
1(3
4536
)
<5 <5 <5 <5 < < < < ,
<5.
<5 <5.
<5 <5 < < < <5.
<5.
<5..0 .0 .0 .0 .2
0
.20
.20
.20
.0 .0 .0 .0 .0 .20
.20
.20
.0 .0 .0
1,2-Di-
chloroethane
total
1(3
2103
)
<0.2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2 .4
< .2
< .2
< .2
1,2-Dichloro-
, propane ,
total
1(3
4541
)
<0.2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< ,2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
Appendix 4
.--Results of
volatile organic
compound analyses of wa
ter
samples
collected
at three
gagi
ng stations in
th
e Wi
ther
s Swash
Basin, Myrtle Be
ach,
S.
C.,
September
1991
through August 1992--Continued
o
[All concentrations in mi
crog
rams
per
liter
except where
indicated; ft /s
, cubic
feet
per
seco
nd;
rec,
recovered;
<, less th
an,-
--,
no data]
Oo
O
Stat
ion
number
021107380
(Mai
nste
m)
021107385
(KOA
)
021107388
(Swash)
Date
09-20-91
09-24
09-24
09-24
07-1
8
07-20
07-20
08-0
3
09-20
09-24
09-24
09-24
09-24
07-18
07-20
08-03
09-24
09-24
09-24
-91
-91
-91
-92
-92
-92
-92
-91
-91
-91
-91
-91
-92
-92
-92
-91
-91
-91
1,3-
Di-
Time
chloropropene,
(hou
rs)
total
1(3
4561
)
0300
<0.2
0
1330
< .20
1635
< .20
1655
< .20
1845
1720
1725
1412
0305
< .20
1330
< .20
1640
< .20
1715
< .20
1805
< .20
1830
1840
1430
1315
< .2
0
2104
< .20
2154
< .20
1,2-trans-Di-
, chloroethene, Mesitylene,
total
tota
l re
c
1(3
4546
) 1(7
7226
)
0.5 .8
< .2
< .2
< .2
<0.2
0
< .2
< .2
0
< .2
< .2
0
< .2
< .2
0
5.1
13 12 4.5
3.0
< .2
< .20
< .2
< .20
< .2
< .2
0
2.0
1.0
1.9
1,3-Dichloro-
benzene ,
total rec
1(3
4566
)
<5.0
<5.0
<5.0
<5.0
< .20
< .20
< .20
< .20
<5.0
<5.0
<5.0
<5.0
<5.0
< .20
< .20
< .2
0
<5.0
<5.0
<5.0
1,3-
Di-
p-Chloro-
1,4-
Di-
2,2-Dichloro-
chloropropane ,
tolu
ene,
chlorobenzene,
propane,
total
total rec
tota
l re
c total
1(7
7173
) 1(7
7277)
1(34571)
1(77170)
<5.0
<5.0
<5.0
<5.0
<0.2
<0.20
< .20
<0.2
< .2
< .2
0 <
.20
< .2
< .2
< .2
0 <
.20
< .2
< .2
< .2
0 <
.20
< .2
<5.0
<5.0
<5.0
<5.0
<5.0
< .2
< .2
0 <
.20
< .2
< .2
< .2
0 <
.20
< .2
< .2
< .2
0 <
.20
< .2
<5.0
<5.0
<5.0
2-Ch
loro
ethy
l-
vinyl
ether,
tota
l 1(3
4576
)
<0.2
< .2
< .2
< .2
<1.0
<1.0
<1.0
<1.0
< .2
< .2
< .2
< .2
< .2
<1.0
<1.0
<1.0
< .2
< .2
< .2
Oo
Appe
ndix
4
--Resu
lts
of volatile or
gani
c co
mpou
nd analyses of water
samples
collected
at th
ree
gaging st
atio
ns in the
Withers
Swas
h Basin, Myrtle Beach,
S.C
, Se
ptem
ber
1991 through August 19
92--Continued
o[A1J co
ncen
trat
ions
in micrograms per
liter
exce
pt where
indicated; ft /s
, cu
bic
feet pe
r second;
rec,
recovered; <, less than,- --,
no data]
Station
number
021107380
(Mainstem)
021107385
(KOA)
021107388
(Swash)
Date
09-2
0-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
07-20-92
08-03-92
09-20-91
09-24-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
08-03-92
09-24-91
09-24-91
09-24-91
Time
Acrolein,
(hours)
total
1(3
4210
)
0300
1330
1635
1655
1845
<20
1720
<20
1725
<20
1412
<20
0305
1330
1640
1715
1805
1830
<20
1840
<20
1430
<20
1315
2104
2154
Carbon
Acrylonitrile,
Benzene, Bromobenzene, Bromoform, tetrachloride,
total
total
total
total
total
1(3
4215
) 1(3
4030
) 1(8
1555
) 1(3
2104
) 1(3
2102
)
<0.2
< .2
< .2
< .2
<20
< .2
<0.2
<20
< .2
<
.2
<20
< .2
< .2
<20
< .2
<
.2
< .2
< .2
< .2
< .2
< .2
<20
< .2
<
.2
<20
< .2
<
.2
<20
< .2
< .2
.6
< .2
< .2
<0.2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
<0 . 2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
, Chlorobenzene,
total
1(34301)
<0.2
0
< .2
0
< .2
0
< .2
0
< .2
0
< .2
0
< .2
0
< .2
0
< .20
.20
< .2
0
< .2
0
< .2
0
.20
< .2
0
< .2
0
< .2
0
< .2
0
< .2
0
Chlorodi-
brom
omet
hane
, total
1(32105)
<0.2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
Chlo
roet
hane
, total
1(3
4311
)
<0.2
< .2
< .2
< .2
< .2
< .2
< .2
< .2 .6 .4 .5 .3 .2 .5
< .2 .4
< .2
< .2
< .2
OO
OO
Appendix 4
Results
of vo
lati
le or
gani
c compound an
alys
es of wa
ter
samp
les
collected
at three
gagi
ng st
atio
ns in the
Withers
Swash
Basi
n, Myrtle Be
ach,
S
C , Se
ptem
ber
1991 th
roug
h August 1992--Continued
o
[Al
J co
ncen
trat
ions
in
mi
crog
rams
per
liter
exce
pt where
indi
cate
d; ft
/s,
cubic
feet pe
r second;
rec,
recovered; <, le
ss th
an;
--,
no da
ta]
Station
number
021107380
09
(Mainstem)
09 09 09 07 07 07 08
0211
0738
=;
09
(KOA
) 09 09 09 09 07 07 08
021107388
09
(Swash)
09 09
Date
-20
-24
-24
-24
-18
-20
-91
-91
-91
- 91
-92
-92
-20-92
-03-9
2
-20-91
-24
-24
-24
-24
-18
-20
-03
-24
-24
-24
-91
-91
-91
-91
-92
-92
-92
-91
-91
-91
Time
(hours)
0300
1330
1635
1655
1845
1720
1725
1412
0305
1330
1640
1715
1805
1830
1840
1430
1315
2104
2154
cis-
1, 2-D
i-
Chlo
rofo
rm,
chloroethene,
tota
l total
1(32106)
1(7
7093
)
<0.2
< .2
< .2
< .2 .2
0.9
.3
.9
.3
.8
< .2
< .2
.8
1.0
1.0 .4
< .2 .6
14
.6
5.8
.6
4.7
< .2
< .2
< .2
cis-l,3-Di-
, chloropropene,
total
1(34704)
<0.2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
Dibr
omo-
Dibromo-
Dich
loro
- , chloropropane,
methane, br
omom
etha
ne,
total
rec
total
rec
total
1(8
2625
) 1(30217)
1(32101)
<0.2
< .2
< .2
< .2
<1.0
<0.2
< .2
<1.0
< .2
< .2
<1.0
< .2
< .2
<1.0
< .2
< .2
< .2
< .2
< .2
< .2
< .2
<1.0
< .2
< .2
<1.0
< .2
< .2
<1.0
< .2
< .2
< .2
< .2
< .2
Dich
loro
di-
, fluoromethane, Et
hylb
enze
ne
tota
l to
tal
1(34668)
1(34371)
<0.2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
<0.2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2 .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
Hexa
chlo
ro-
, butadiene,
tota
l 1(3
9702
)
<5.0
<5.0
<5.0
<5.0
<0.2
< .2
< .2
< .2
<5.0
<5.0
<5.0
<5.0
<5.0
< .2
< .2
< .2
<5.0
<5.0
<5.0
Appe
ndix
4.-
Results
of vo
lati
le organic
compound analyses of wa
ter
samples
collected
at th
ree
gaging stations in the
With
ers
Swash
Basi
n, My
rtle
Be
ach,
S.
C.,
September
1991 through
Augu
st 1992--Continued
Q
[All co
ncen
trat
ions
in mi
crog
rams
pe
r liter
except where
indicated; ft
/s,
cubi
c feet per
second/
rec,
recovered;
<, le
ss th
an;
--,
no data]
Oo
Stat
ion
number
0211
0738
0(M
ains
tem)
021107385
(KOA
)
021107388
(Swa
sh)
Date
09-20-
09-24-
09-24-
09-24-
07-18-
07-20-
07-20-
08-03-
91 91 91 91 92 92 92 92
09-20-91
09-24-
09-24-
09-24-
09-24-
07-18-
07-20-
08-03-
09-24-
09-24-
09-24-
91 91 91 91 92 92 92 91 91 91
Isopropyl-
Time
benzene,
(hou
rs)
total rec
X(77223)
0300
1330
1635
1655
1845
<0.20
1720
< .20
1725
< .20
1412
< .20
0305
1330
1640
1715
1805
1830
< .20
1840
< .20
1430
< .20
1315
2104
2154
Methyl
bromide,
total
1(34413)
<0 . 2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< ,2
< .2
< .2
< 2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
Methyl
chloride,
total
1(34418)
<0.2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
Meth
ylen
e chloride,
n-Butylbenzene,
total
total
rec
1(34423)
1(77342)
<0 . 2
< .2
< .2
< .2
< .2
<0.20
< .2
< .20
< .2
< .2
0
< .2
< .2
0
< .2
< .2 .8 .3 .2
< .2
< .2
0
< .2
< .20
< .2
< .20
< .2
< .2
< .2
n-Pr
opyl
benz
ene,
Na
phth
alen
e,
total
rec
tota
l 1(77224)
1(34696)
<5.0
<5.0
<5.0
<5.0
<0.20
<0.2
< .20
< .2
< .2
0 <
.2
< .20
< .2
<5.0
<5.0
<5.0
<5.0
<5.0
< .20
< .2
< .20
< .2
< .20
< .2
<5.0
<5.0
<5.0
p-Isopropyl-
sec-
Buty
l -
tolu
ene,
be
nzen
e,
total
rec
total
rec
1(77356)
1(77350)
__ __ --
<0.2
0 <0.20
< .20
< .20
< .20
< .20
< .20
< .20
._ __ ._ __ -- .30
< .20
< .20
< .20
< .20
< .20
__ __
Appe
ndix
4.--Results
of vo
lati
le or
gani
c compound analyses of water
samples
collected
at three
gaging stations in the
Withers
Swash
Basi
n, My
rtle
Beach,
S.C.
, September
1991 through
August 19
92--
Continued
[All co
ncen
trat
ions
in
mic
rogr
ams
per
lite
r except where
indicated; ft /s
, cu
bic
feet per second;
rec, recovered; <,
le
ss than,- --,
no data]
Station
number
021107380
(Mai
nste
m)
0211
0738
5(K
OA)
0211
0738
8(S
wash
)
Date
09-20-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
07-20-92
08-03-92
09-20-91
09-24-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
08-03-92
09-24-91
09-24-91
09-24-91
Time
(hou
rs)
0300
1330
1635
1655
1845
1720
1725
1412
0305
1330
1640
1715
1805
1830
1840
1430
1315
2104
2154
Styr
ene,
total
1(77128)
<0.2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
< .2
tert
-But
yl-
Tetr
achl
oro-
be
nzen
e,
ethy
l en
e,
Tolu
ene,
total
rec
total
total
1(77353)
1(34475)
1(34010)
<0 <
- -
< ,
- -
< .
<0.20
< .
< .2
0 <
.
< .2
0 <
.
< .2
0 <
.
- -
< .
< .
< .
- -
< .
< .
< .2
0 <
.
< .2
0 <
,
< .2
0 <
.
__ -- --
.2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .3 .2
<0.2
< .2
< .2
< .2
< .2
< .2
< .2
< .2 .2
< .2 .8 .3
< .2 .9 .4 .3
< .2
< .2
< .2
trans-l,3-Di-
Trichloro-
chloropropene,
ethyl ene,
total
total
1(3
4699
) 1(3
9180
)
<0.
< .
< .
< .
< .
< .
< ,
< .
< .
< .
< .
< .
< .
< .
< .
< .
< .
< .
< ..2 .2 .2 .2 .2 ,2 .2 .2 ,2 .2 .2 .2 .2 .2 ,2 2 .2 .2 .2
<0 < < < < < < <
5 12 15
8 5
10
6
48
2. 1. 2.
.2 .2 .2 .2 .2 .2 .2 .2 .2 .8 .4 .5 .4 .2 .6
Tric
hlor
o-
f luo
rome
than
e ,
total
1(34488)
<0.
< < .
< < < < < ,
< .
< ,
< .
< < .
< .
< ,
< ,
< .
< .
< ..2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2
Vinyl
chloride
total
1(39175)
<0.2
< .2
< .2
< .2 .2 .2 .2
< .2 .3 .5
1.0 .2
< .2
1.2
< .2 .3
< .2
< .2
< .2
Xyle
ne,
total
rec
1(81551)
<0.
< < ,
< .
< ,
< ,
< ,
< .
< .
< .
< .
< .
< .
< .
< .
< ..2
0
.20
.20
.20
.20
.20
.20
.20
.20
.20
.50
.20
.20
.20
.20
.20
.20
.20
.20
^Par
amet
er co
de,
National Water
Data
St
orag
e and
Retrieval
System of
the
U.S. Geological Su
rvey
.
APPENDIX 5
Results of acid- and base/neutral-extractable organic compound analyses of water samples collected at three gaging stations in the Withers Swash Basin, Myrtle Beach, S.C., September 1991 through August 1992
91
Appe
ndix
5.
--Re
sult
s of acid-
and ba
se/n
eutr
al-e
xtra
ctab
le or
gani
c co
mpou
nd analyses of water
samples
coll
ecte
d at th
ree
gaging stations in th
e Withers
Swas
h Ba
sin,
My
rtle
Be
ach,
S.C.,
September
1991 through August 1992
[ft
/s,
cubic
feet per
seco
nd;
rec,
re
cove
red;
mg
/L,
milligrams pe
r li
ter,
- jtg/L, mi
crog
rams
pe
r liter,-
<, less th
an;
--,
no data]
O ro
Station
number
021107380
(Mainstem)
021107385
(KOA)
021107388
(Swash)
Date
09-20-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
07-20-92
08-03-92
09-20-91
09-24-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
08-03-92
09-24-91
09-24-91
09-24-91
Oil
and
1,2,5,6-Dibenz-
1,2-
Diph
enyl
- Di
scha
rge,
grease,
anthracene,
hydr
azin
e,Time
instantaneous
total
rec
total
total
rec
3 /
(hours)
(ft
/s)
(mg/
L)
(Mg/
L)
(Mg/
L)
1(00061)
1(0
0556
) 1(34556)
1(8
2626
)
0300
1.1
1 <10.0
<5.0
1330
.60
<1
<10.0
<5.0
1635
17
3 <10.0
<5.0
1655
11
3 <10.0
<5.0
1845
.60
<1
1720
1.3
<1
1725
1.8
<1
1412
10
1
0305
2.1
1 <10.0
<5.0
1330
1.5
2 <10.0
<5.0
1640
5.2
2 <10.0
<5.0
1715
5.3
2 <10.0
<5.0
1805
3.2
1 <10.0
<5.0
1830
1.6
<1
1840
2.5
<1
1430
17
1
1315
--
1 <10.0
<5.0
2104
--
<1
<10.0
<5.0
2154
--
1 <10.0
<5.0
2,4,6-Tri-
2,4-Di-
2,4-Di-
2,4-Di-
2,4-Dinitro-
chlorophenol ,
chlorophenol ,
methylphenol ,
nitrophenol,
toluene,
total
total
total
total
total
(Mg/
L)
(Mg/L)
(Mg/
L)
(Mg/
L)
(Mg/
L)
1(34621)
1(34601)
1(3
4606
) 1(34616)
1(34611)
<20.0
<5.0
<5.0
<20.0
<5.0
<20.0
<5.0
<5.0
<20.0
<5.0
<20.0
<5.0
<5.0
<20.0
<5 . 0
<20.0
<5.0
<5.0
<20.0
<5.0
__ _- -- --
<20.0
<5.0
<5.0
<20.0
<5 . 0
<20.0
<5.0
<5.0
<20.0
<5.0
<20.0
<5.0
<5.0
<20.0
<5 . 0
<20.0
<5.0
<5.0
<20.0
<5 . 0
<20.0
<5.0
<5.0
<20.0
<5 . 0
__ -- --
<20.0
<5.0
<5.0
<20.0
<5 . 0
<20.0
<5.0
<5.0
<20.0
<5.0
<20.0
<5.0
<5.0
<20.0
<5 . 0
Appe
ndix
5. --Results of ac
id-
and ba
se/n
eutr
al-e
xtra
ctab
le or
gani
c co
mpou
nd analyses of water
samp
les
collected
at three
gagi
ng stations in
the
Withers
Swas
h Ba
sin,
My
rtle
Beach, S.C.,
September
1991 th
roug
h Au
gust
19
92- -C
onti
nued
[ft3/s, cubic
feet
per
seco
nd;
rec,
re
cove
red;
mg
/L,
milligrams pe
r li
ter,
-mi
crog
rams
per
liter,-
<, le
ss th
an,-
--,
no da
ta]
Station
Date
number
021107380
09-20-91
(Mainstem)
09-2
4-91
09-2
4-91
09-24-91
07-18-92
07-20-92
07-20-92
,O
08-03-92
GO
021107385
09-20-91
(KOA
) 09-24-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
08-03-92
021107388
09-24-91
(Swash)
09-24-91
09-24-91
Time
(hou
rs)
0300
1330
1635
1655
1845
1720
1725
1412
0305
1330
1640
1715
1805
1830
1840
1430
1315
2104
2154
2,6-
Dini
tro-
toluene,
tota
l
(Mg/D
1(34626)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
2-Chloro-
naphtalene ,
total
(/xg
/L)
1(34581)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
2-Chloro-
phenol ,
tota
l
(M9/
L)
1(3
4586
)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
2-Ni
tro-
phenol ,
total
(Mg/
L)
1(34591)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
3,3'
-Dichloro-
benzidine,
total
(Mg/
L)
1(34631)
<20.0
<20.0
<20.0
<20.0 -- -- -- --
<20.0
<20.0
<20.0
<20.0
<20.0 -- -- --
<20.0
<20.0
<20.0
4, 6-Dinitro-
orthocresol,
total
(Mg/
L)
x(3
4657
)
<30.0
<30.0
<30.0
<30.0 -- -- -- --
<30.0
<30.0
<30.0
<30.0
<30.0 -- -- --
<30.0
<30.0
<30.0
4 - Bromophenyl
phen
yl et
her,
total
(Mg/L)
1(346
36)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
4 - Chl
orop
heny
l phenyl et
her,
total
(Mg/L)
1(34641)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
4-Nitro-
phenol ,
total
(Mg/
L)
1(34646)
<30.0
<30.0
<30.0
<30.0 _- -- -- --
<30.0
<30.0
<30.0
<30.0
<30.0 -- -- --
<30.0
<30.0
<30.0
Acenaphthene ,
total
(Mg/L)
1(34205)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
Appendix 5.--Results
of ac
id-
and base/neutral-extractable or
gani
c compound analyses of water
samp
les
collected
at three
gagi
ng stations in th
e Withers
Swas
h Basin, Myrtle Beach, S.
C.,
September
1991 through
August 1992--Continued
Q
[ft
/s,
cubi
c feet per
second;
rec, re
cove
red;
mg
/L,
milligrams per
liter; j*g/L, micrograms per
liter;
<, le
ss th
an;
--,
no da
ta]
Stat
ion
number
021107380
(Mainstem)
021107385
(KOA
)
021107388
(Swa
sh)
Date
09-20-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
07-20-92
08-03-92
09-20-91
09-24-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
08-03-92
09-24-91
09-24-91
09-24-91
Time
(hou
rs)
0300
1330
1635
1655
1845
1720
1725
1412
0305
1330
1640
1715
1805
1830
1840
1430
1315
2104
2154
Acenaphthylene ,
total
1(34200)
<5.0
<5.0
<5.0
<5.0 -- - --
-
<5.0
<5.0
<5.0
<5.0
<5.0 -- --
<5.0
<5.0
<5.0
Anthracene,
total
1(3
4220
)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
Benz
idin
e,
total
1(39120)
<40.0
<40.0
<40.0
<40.0 -- -- -- --
<40.0
<40.0
<40.0
<40.0
<40.0 -- -- --
<40.0
<40.0
<40.0
Benzo (a) -
pyrene ,
total
(Mg/
L)
1(34247)
<10.0
<10.0
<10.0
<10.0 -- -- -- --
<10.0
<10.0
<10.0
<10.0
<10.0 -- -- --
<10.0
<10.0
<10.0
Benz
o (b)
- fl
uora
nthe
ne,
total
(Mg/
L)
1(34230)
<10.0
<10.0
<10.0
<10.0 -- -- -- --
<10.0
<10.0
<10.0
<10.0
<10.0 -- -- --
<10.0
<10.0
<10.0
Benzo (k)
-
fluoranthene ,
total
X(3
4242
)
<10.0
<10.0
<10.0
<10.0 -- -- -- --
<10.0
<10.0
<10.0
<10.0
<10.0 -- -- --
<10.0
<10.0
<10.0
Benzo (a)
-
anthracene,
total
(Mg/
L)
1(3
4526
)
<10.0
<10.0
<10.0
<10.0 -- -- -- --
<10.0
<10.0
<10.0
<10.0
<10.0 -- -- --
<10.0
<10.0
<10.0
Benzo (ghi)
pery
lene
, total
(Mg/
L)
1(34521)
<10.0
<10.0
<10.0
<10.0 -- -- -- --
<10.0
<10.0
<10.0
<10.0
<10.0 -- -- --
<10.0
<10.0
<10.0
bis(
2-Ch
loro
- ethoxy)
- me
than
e ,
total
(Mg/L)
1(34278)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
bis (2-
Chloroethyl )
ether,
total
1(34273)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 __ -- --
<5.0
<5.0
<5.0
Appe
ndix
5.--Resu
lts
of acid-
and ba
se/n
eutr
al-e
xtra
ctab
le or
gani
c co
mpou
nd analyses of water
samples
collected
at three
gagi
ng stations in th
e Wi
ther
s Swas
h Ba
sin,
My
rtle
Beach, S.C.,
September
1991 th
roug
h Au
gust
1992--Continued
[ft
/s,
cubic
feet per
seco
nd;
rec,
re
cove
red;
mg
/L,
mill
igra
ms per
liter,-
^g/L
, mi
crog
rams
per
lite
r;
<, le
ss than;
--,
no da
ta]
>O
Cn
Station
numb
er
021107380
(Mainstem)
021107385
(KOA)
021107388
(Swash)
Date
09-20-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
07-20-92
08-03-92
09-20-91
09-24-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
08-03-92
09-24-91
09-24-91
09-24-91
Time
(hours)
0300
1330
1635
1655
1845
1720
1725
1412
0305
1330
1640
1715
1805
1830
1840
1430
1315
2104
2154
bis (2-Chloro-
isopropyl)
ethe
r,
tota
l
(M9/L)
1(34283)
<5.0
<5.0
<5.0
<5.0 -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
bis(
2-
Ethylhexyl)-
phth
alat
e,
total
(Mg/D
1(39100)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
n- But
ylbe
nzyl
-
phthalate,
total
(M9/
L)
1(34292)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
Para
chlo
ra-
meta
cres
ol,
total
(M9/
L)
1(34452)
<30.0
<30.0
<30.0
<30.
0 -- -- -- --
<30.0
<30.0
<30.
0
<30.
0
<30.0 -- --
<30.
0
<30.0
<30.0
Chry
sene
,
total
(M9/D
1(34320)
<10.0
<10.0
<10.
0
<10.
0 -_ -- -- --
<10.
0
<10.
0
<10.
0
<10.
0
<10.
0 -- -- --
<10.
0
<10.0
<10.
0
Di-n
-but
yl
phthalate,
tota
l
(M9/L)
1(39110)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
Di-n-octyl
phthalate,
total
(M9/D
1(34596)
<10.
0<10.0
<10.
0<10.0 -- -- -- --
<10.0
<10.0
<10.0
<10.0
<10.0 __ -- --
<10.0
<10.0
<10.0
Diet
hyl
phthalate,
tota
l
(M9/D
1(34336)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
Dimethyl
phth
alat
e,
tota
l
(M9/
L)
1{34341)
<5.0
<5.0
<5.0
<5.0 -_ -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -_ -- --
<5.0
<5.0
<5.0
o
Appe
ndix
5.
--Re
sult
s of acid-
and
base
/neu
tral
-ext
ract
able
organic
compound analyses of water
samp
les
collected
at three
gagi
ng st
atio
ns in the Withers
Swas
h Basin, Myrtle Beach, S.C.,
September
1991 th
roug
h Au
gust
1992--Continued
[ft
/s,
cubic
feet per
seco
nd;
rec,
re
cove
red;
mg
/L,
milligrams per
li
ter;
/x
g/L,
micrograms pe
r liter,-
<, le
ss th
an,-
--,
no data]
Station
numb
er
021107380
(Mainstem)
021107385
(KOA
)
021107388
(Swash)
Date
09-2
0-91
09-2
4-91
09-2
4-91
09-2
4-91
07-1
8-92
07-2
0-92
07-20-92
08-0
3-92
09-2
0-91
09-2
4-91
09-2
4-91
09-2
4-91
09-2
4-91
07-1
8-92
07-2
0-92
08-0
3-92
09-2
4-91
09-2
4-91
09-2
4-91
Time
(hours)
0300
1330
1635
1655
1845
1720
1725
1412
0305
1330
1640
1715
1805
1830
1840
1430
1315
2104
2154
Fluo
rant
hene
, to
tal
X(34376)
<5.0
<5.0 7.0
<5.0 -- -- -- --
<5.0
<5.0 5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
Fluorene ,
tota
l
1(34381)
<5.0
<5.0
<5.0
<5.0 _- -- -- --
<5.0
<5.0
. <5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
Hexa
chlo
ro-
benzene
, total
1(39700)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
Hexa
chlo
ro-
butadiene,
total
1(39702)
<5.0
<5.0
- <5.0
<5.0 _- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
Hexa
chlo
rocy
clo-
pe
ntad
iene
, total
1(34386)
<5.0
<5.0
<5.0
<5.0 __ -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 _- -- --
<5.0
<5.0
<5.0
Hexa
chlo
ro-
etha
ne,
total
1(3
4396)
<5.0
<5.0
<5.0
<5.0 __ -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -_ -- --
<5.0
<5.0
<5.0
Inde
no-
pyre
ne ,
total
1(34403)
<10.0
<10.0
<10.0
<10.0 -- -- --
<10.0
<10.0
<10.
0<10.0
<10.0 __ -- --
<10.0
<10.0
<10.0
Isop
horo
ne,
tota
l
1(3
4408
)
<5.0
<5.0
<5.0
<5.0 __ -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 __ -- --
<5.0
<5.0
<5.0
n-Nitrosodi-
prop
ylam
ine,
total
1(3
4428
)
<5.0
<5.0
<5.0
<5.0 __ -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 __ -- --
<5.0
<5.0
<5.0
O
Appe
ndix
5.
--Re
sult
s of ac
id-
and ba
se/n
eutr
al-e
xtra
ctab
le organic
compound analyses of water
samples
collected
at three
gaging stations in the
Withers
Swash
Basi
n, Myrtle Be
ach,
S.
C.,
September
1991 through
August 19
92--
Cont
inue
d
[ft
/s,
cubic
feet per
seco
nd;
rec,
re
cove
red;
mg/L,
mill
igra
ms per
liter,-
/ig/L, mi
crog
rams
per
lite
r; <, le
ss than,- --,
no data]
Stat
ion
number
021107380
(Mainstem)
021107385
(KOA
)
021107388
(Swash)
Date
09-2
0-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
07-20-92
08-03-92
09-20-91
09-24-91
09-24-91
09-24-91
09-24-91
07-18-92
07-20-92
08-03-92
09-24-91
09-24-91
09-24-91
Time
(hou
rs)
0300
1330
1635
1655
1845
1720
1725
1412
0305
1330
1640
1715
1805
1830
1840
1430
1315
2104
2154
n-Ni
tros
odi-
methylamine,
tota
l
1(3
4438
)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
n-Ni
tros
odi-
phenylamine,
total
(/ig
/L)
1(34433)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
Naphthalene,
total
1(34696)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
Nitr
oben
zene
, to
tal
(/ig/L)
1(34447)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
Pentachloro-
phenol ,
total
(/ig/L)
1(3
9032
)
<30.0
<30.0
<30.0
<30.0 -- -- -- --
<30.
0
<30.0
<30.0
<30.0
<30.0 -- -- --
<30.0
<30.0
<30.0
Phen
anth
rene
, total
(/ig/L)
1(34461)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
Phenol
total
(Atg
/L)
1(3
4694
)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
Phen
ols,
total
1(32730)
2 1 3 3
-- -- -- --
3 1 3 3 1
-- -- --
1 1 1
Pyre
ne,
tota
l
1(3
4469
)
<5.0
<5.0
<5.0
<5.0 -- -- -- --
<5.0
<5.0
<5.0
<5.0
<5.0 -- -- --
<5.0
<5.0
<5.0
Para
mete
r code,
National Wa
ter
Data
Storage
and
Retr
ieva
l System of the
U.S. Ge
olog
ical
Su
rvey
.
APPENDIX 6
Results of selected pesticide analyses of water samples collected at three gaging stations in the Withers Swash Basin, Myrtle Beach, S.C, September 1991 through August 1992
98
o
o
Appe
ndix
6
--Results
of selected pesticide analyses of wa
ter
samples
coll
ecte
d at three
gaging stations in th
e Wi
ther
s Swash
Basi
n, My
rtle
Beach, S.C.
Sept
embe
r 19
91 th
roug
h August 1992
[ft
/s,
cubic
feet per
seco
nd;
/xg/L, micrograms pe
r li
ter,
- re
c, recovered; DDD, dichlorodiphenyldichloroethane;
DDE, di
chlo
rodi
phen
yldi
chlo
roet
hyle
ne;
DOT, di
chlo
rodi
phen
yltr
ichl
oroe
than
e,-
PCB,
polychlorinated b
iphe
nyls
,- <, less th
an,-
--,
no da
ta]
Station
number
021107380
(Mainstem)
021107385
(KOA
)
021107388
(Swa
sh)
Date
09-20-91
09-24-91
09-24-91
09-24-91
07-20-92
07-20-92
08-03-92
09-20-91
09-24-91
09-24-91
09-24-91
09-24-91
07-20-92
08-03-92
09-24-91
09-24-91
09-24-91
Time
(hours)
0300
1330
1635
1655
1720
1725
1412
0305
1330
1640
1715
1805
1840
1430
1315
2104
2154
alpha- Benzene
Discharge,
Aldrin, hexachloride,
instantaneous
total
total
(ft3/s
) (/
/g/L
) (pig/L)
1(0
0061
) 1(39330)
1(3
9337
)
1.1
<0.010
.60
< .010
17
< .0
10
11
< .0
10
1.3
< .0
40
<0.03
1.8
< .040
< .03
10
< .040
< .03
2.1
< .0
10
1.5
< .010
5.2
< .0
10
5.3
< .0
10
3.2
< .010
2.5
< .040
< .03
17
< .0
40
< .03
< .010
< .0
10
< .0
10
beta
-Ben
zene
de
lta-
Benz
ene
hexachloride,
hexa
chlo
ride
, Ch
lord
ane,
tr
ans-
Chlo
rdan
e,
total
total
total
tota
l
(//g
/L)
(A<g
/L)
(/xg
/L)
(A<g
/L)
1(39338)
1(34259)
1(39350)
1(39065)
<0.1
< .1
- -
- -
3 - -
.1
<0.03
<0.09
< .1
<0.10
< .03
< .0
9 <
.1
< .1
0
< .03
< .09
.2
< .1
0
< .1
< .1
< .1
< .1
< .1
< .03
< .09
< .1
<
.10
< .03
< .09
< .1
< .10
< .1
< .1
< .1
, cis-Chlordane,
ODD,
total
total
(//g/L)
(/*g/L)
1(39062)
1(39360)
<0.010
< .0
10
.030
.010
<0.10
< .10
< .1
0
< .0
10
< .0
10
< .0
10
< .010
< .010
< .1
0
< .10
< .010
< .0
10
< .0
10
o o
Appendix 6,
--Re
sult
s of selected pesticide analyses of water
samples
collected
at three ga
ging
stations in th
e Withers
Swas
h Ba
sin,
My
rtle
Be
ach,
S.C.
September
1991 th
roug
h Au
gust
19
92--
Cont
inue
d
[ft
/s,
cubi
c fe
et per
second;
jig/L, micrograms per li
ter;
rec, recovered; OD
D, di
chlo
rodi
phen
yldi
chlo
roet
hane
; DDE, di
chlo
rodi
phen
yldi
chlo
roet
hyle
ne,-
DOT, di
chlo
rodi
phen
yltr
ichl
oroe
than
e,-
PCB,
po
lych
lori
nate
d bi
phen
yls;
<, less th
an,-
--,
no data]
Stat
ion
number
021107380
(Mainstem)
Date
09 09 09 09 07
-20
-24
-24
-24
-20
-91
-91
-91
-91
-92
07-20-92
021107385
(KOA)
021107388
(Swash)
08 09 09 09 09 09 07 08 09 09 09
-03-9
2
-20-91
-24
-24
-24
-24
-20
-03
-24
-24
-24
-91
-91
-91
-91
-92
-92
-91
-91
-91
Time
(hou
rs)
0300
1330
1635
1655
1720
1725
1412
0305
1330
1640
1715
1805
1840
1430
1315
2104
2154
Endosulfan,
Endosulfan,
p,p'
-DDD
, DD
E,
p,p'
-DDE
, DO
T,
p,p'
-DO
T,
Dieldrin,
Endosulfan,
alpha,
beta
, to
tal
tota
l to
tal
total
tota
l total
total
tota
l rec
total
(Mg/L)
(Mg/D
(Mg/D
(/*g
/L)
(ng/
L)
(ng/L)
(ng/
L.)
(/zg/L)
(/zg/L)
1(3
9310
) 1(39365)
1(3
9320
) 1(3
9370
) 1(39300)
1(3
9380
) 1(39388)
1(3
4361
) 1(34356)
<0.010
--
<0.010
--
<0.010
<0.010
< .0
10
--
< .0
10
--
< .0
10
< .010
.020
--
.030
--
.010
< .0
10
.010
--
< .010
--
.010
< .0
10
<0.10
--
<0.04
--
<0.10
< .0
20
--
<0.10
<0.04
< .1
0 --
< .04
--
< .1
0 <
.020
--
< .1
0 <
.04
< .10
--
< .0
4 --
<
.10
< .0
20
--
< .1
0 <
.04
< .0
10
--
< .0
10
--
< .0
10
< .010
< .010
--
< .0
10
--
< .0
10
< .0
10
< .0
10
--
< .0
10
--
< .0
10
< .0
10
< .0
10
--
< .0
10
--
< .0
10
< .0
10
< .010
--
< .0
10
--
< .0
10
< .010
< .10
--
< .04
--
< .1
0 <
.020
--
< .10
< .04
< .10
--
< .0
4 --
<
.10
< .0
20
--
< .10
< .04
< .0
10
--
< .0
10
--
< .0
10
< .0
10
< .0
10
--
< .0
10
--
< .0
10
< .0
10
< .0
10
--
< .0
10
--
< .0
10
< .0
10
Endosulfan,
sulfate,
total
(ng/L)
1(34351)
-- -- --
<0.6
0<
.60
< .60
-- -- -- --
< .60
< .60
-- --
Appe
ndix
6. --Res
ults
of
selected pe
stic
ide
analyses of wa
ter
samples
collected
at th
ree
gaging st
atio
ns in th
e Wi
ther
s Sw
ash
Basi
n, Myrtle Be
ach,
S.C.
Sept
embe
r 199[ th
roug
h Au
gust
19
92- -Continued
[ft
/s,
cubi
c feet pe
r se
cond
;, micrograms per
liter,-
rec,
re
cove
red;
DDD, di
chlo
rodi
phen
yldi
chlo
roet
hane
,-DD
E, di
chlo
rodi
phen
yldi
chlo
roet
hyle
ne;
DDT,
di
chlo
rodi
phen
yltr
ichl
oroe
than
e; PC
B, polychlorinated bi
phen
yls;
<, less than,- --,
no data]
Station
numb
er
021107380
(Mainstem)
021107385
(KOA
)
021107388
(Swash)
Date
09-20-91
09-24-91
09-24-91
09 24-91
07 20-92
07-20-92
08-03-92
09-20-91
09-24-91
09-24-91
09-24-91
09-24-91
07-20-92
08-03-92
09-24-91
09-24-91
09-24-91
Time
(h
ours
)
0300
1330
1635
1655
1720
1725
1412
0305
1330
1640
1715
1805
1840
1430
1315
2104
2154
Endr
in,
Endrin aldehyde
total
rec
total
1(39390)
1(3
4366
)
<0.010
< .010
< .0
10
< .010
< .0
60
<0.20
< .0
60
< .20
< .060
< .20
< .0
10
< .0
10
< .010
< .010
< .010
< .060
< .20
< .060
< .20
< .0
10
< .0
10
< .010
Hept
achl
or,
total
1(39410)
<0.
< < < < .
< .
< .
< < .
< .
< < .
< < < ,
< ,.0
10
.010
.010
.010
.030
.030
,030
.010
.010
.010
.010
.010
.030
.030
.010
,010
,010
Heptachlor
epoxide,
total
1(39420)
<0.010
< .010
< .010
< .010
< .80
< .80
< .80
< .0
10
< .010
< .0
10
< .010
< .010
< .80
< .80
< .010
< .0
10
< .0
10
Lindane
, Methoxychlor ,
total
total
1(39340)
1(3
9480
)
<0.010
<0.01
< .010
< .0
1
< .010
< .0
1
< .010
< .0
1
< .0
30
< .030
< .030
< .0
10
< .01
< .010
< .0
1
< .010
< .01
< .010
< .0
1
< .010
< .01
< .030
< .030
< .0
10
< .01
< .0
10
< .0
1
< .0
10
< .01
Mi rex ,
Perthane ,
Toxaphene
, total
total
total
1(39755)
1(39034)
1(39400)
<0.01
<0.1
<1
< .01
< .1
<1
< .0
1 <
.1
<1
< .0
1 <
.1
<1
<2 <2 <2
< .0
1 <
.1
<1
< .01
< .1
<1
< .0
1 <
.1
<1
< .01
< .1
<1
< .0
1 <
.1
<1
<2 <2
< .01
< .1
<1
< .0
1 <
.1
<1
< .01
< .1
<1
Appe
ndix
6.
--Re
sult
s of selected pesticide analyses of water
samples
collected
at th
ree
gagi
ng stations in the
With
ers
Swash
Basin, Myrtle Be
ach,
S.
C.
September
1991
th
roug
h August 19
92--
Cont
inue
d
[ft
/a,
cubic
feet per
second;
/xg/L, micrograms per
lite
r,-
rec, recovered; DD
D, di
chlo
rodiphenyldichloroethane;
DDE, di
chlo
rodi
phen
yldi
chlo
roet
hyle
ne;
DDT,
di
chlo
rodi
phen
yltr
ichl
oroe
than
e; PC
B, polychlorinated
biphenyls; <, le
ss than,- --,
no data]
0 ro
c: ;
GOVLRNMCNTPn
Station
Date
numb
er
021107380
09-20-91
(Mai
nste
m)
09-2
4-91
09-24-91
09-24-91
07-20-92
07-20-92
08-03-92
021107385
09-20-91
(KOA)
09-24-91
09-24-91
09-24-91
09-24-91
07-20-92
08-03-92
021107388
09-24-91
(Swash)
09-24-91
09-24-91
Time
(hou
rs)
0300
1330
1635
1655
1720
1725
1412
0305
1330
1640
1715
1805
1840
1430
1315
2104
2154
PCB,
total
1(3
9516
)
<0.1
< .1
< .1
< .1 -- -- --
< . 1
< .1
< .1
< .1
< .1 -- --
< .1
< .1
< .1
Aroclor
Aroclor
Aroclor
Aroclor
Aroclor
Aroclor
Aroclor
Polychlorinated
1016 PCB,
1221
PC
B,
1232 PCB,
1242 PC
B,
1248 PC
B,
1254 PC
B,
1260 PC
B,
naphthalenes,
tota
l total
total
total
total
total
total
total
(/xg/L)
(/xg/L)
(/xg/L)
(/xg/L)
(/xg/L)
(/xg
/L)
(/xg/L)
(/xg
/L)
1(3
4671
) 1(3
9488
) X(3
9492
) 1(3
9496
) 1(3
9500
) 1(39504)
1(3
9508
) 1(3
9250
)
<0.10
< .10
_.
<
_10
< .1
0
<o.i
<i.o
<o.i
<o.i
<o.i
<o.i
<o.i
< .1
<1.0
<
.1
< .1
< .1
< .1
< .1
< .1
<1.0
<
.1
< .1
< .1
< .1
< .1
< .10
< .1
0
< .10
< .1
0
< .1
0
< .1
<1.0
<
.1
< .1
< .1
< .1
< .1
< .1
<1.0
<
.1
< .1
< .1
< .1
<
.1
< .10
< .1
0
< .10
Parameter
code,
Nati
onal
Wa
ter
Data St
orag
e and
Retr
ieva
l Sy
stem
of the
U.S. Ge
olog
ical
Su
rvey
.