United States
Environmental Protection
Agency
Region 4
345 Courtland Street, NE
Atlanta, GA 3036§
EPA 904/9-85 139
October 1985
^CDA The Impacts of Wastewater Disposal
Practices on the Ground Water of the
North Carolina Barrier Islands
Final Report
ATLANTIC OCEAN
Atlomic Booch/PIno
Knoll Shoro3 Study Aroa
Surf City
Study Area
10 20 30milos
Wilmington
VIRGINIA
NORTH CAROLINA
Kill Devil Hills
Study Area
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_ The Impacts of Wastewater Disposal Practices on
the Ground Water of the North Carolina Barrier Islands
FINAL REPORT
September, 1985
Prepared by
U.S. Environmental Protection Agency
Region IV, Atlanta, Georgia 30365
In January 1984, EPA published a Final Environmental impact
Statement (EIS) that identified the need for estimating the
impacts of present wastewater treatment and disposal prac-
tices on the North Carolina barrier islands. The EIS iden-
tified increases in groundwater levels associated with the
addition of wastewater to the water table and changes in
groundwater quality as two areas of impact having the
greatest significance.
This study examines these impacts for three areas of the
North Carolina barrier islands; Kill Devil Hills, Atlantic
Beach/Pine Knoll Shores and Surf City. The study has two
primary objectives. One objective is to develop a simple
model for computing groundwater level changes caused by
disposal of wastewater to the shallow aquifer system. The
second objective is to estimate the impact of the wastewater
disposal on groundwater quality. Field work for the study
was conducted July 1984 through Nay 1985.
The study determined that the disposal of wastewater had a
minor impact on the water quality of the shallow aquifers at
Kill Devil Hills and Surf City. Wastewater disposal had some
impact on shallow groundwater quality in the Atlantic
Beach/Pine Knoll Shores study area. The study also showed
that wastewater disposal had resulted in increased ground-
water levels in each of the study areas. The simple model
was used to predict these water level impacts.
This report contains all data, analyses and conclusions
resulting from this study. Comments or inquires should be
forwarded to Robert B. Howard, Chief, NEPA Compliance Section,
U.S. EPA - Region IV, 345 Courtland Street, N.E., Atlanta,
Georgia 30365 (404) 881-3776.
HP BO 19Q$
iate
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THE IMPACTS OF WASTEWATER DISPOSAL PRACTICES ON THE
GROUND WATER OF THE NORTH CAROLINA BARRIER ISLANDS
Prepared by
U.S. ENVIROtMENTAL PROTECTION AGENCY, REGION IV
ATLANTA, GEORGIA
With Assistance from
APPLIED BIOLOGY, INC.
DECATUR, GEORGIA
SEPTEMBER 1985
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ACKNOWLEDGMENTS
Much of the information 1n this report was obtained through the
generous support and cooperation of the following:
North Carolina Department of Natural Resources and Community
Development
Town of Kill Devil Hills
Town of Atlantic Beach
Town of Pine Knoll Shores
Town of Surf City
Inquiries regarding information in this handbook should be made to
U.S. Environmental Protection Agency, Region IV, Environmental Assessment
Branch, 345 Courtland Street, Atlanta, Georgia, 30365.
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LIST OF PREPARERS
U.S. Environmental Protection Agency
Robert B. Howard
Robert Lord
W. Bowman Crum
Nancy W. Walls, Ph.D.
Robert S. McLeod, P.E.
Kenneth Stockwell
Robert Comegys
Steven C. Wiedl
Applied Biology, Inc.
Project Officer
Project Monitor
Project Monitor
Project Manager
Project Director
Water Resources Specialist
Environmental Scientist
Environmental Scientist
Gannett Fleming Corddry and Carpenter, Inc.
Thomas M. Rachford, Ph.D.
Project Manager
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TABLE OF CONTENTS
EXECUTIVE SUMMARY 1
1.0 INTRODUCTION 1-1
1.1 Study Objectives 1-1
1.2 Approach 1-3
2.0 HYDROLOGIC FIELD DATA COLLECTION PROGRAM 2-1
2.1 Installation of Monitoring Wells 2-1
2.1.1 Transect Locations 2-1
2.1.2 Well Sites and Well Construction 2-6
2.2 Installation of Tidal Gauges 2-13
2.3 Aquifer Testing 2-13
2.4 Transect Profile and Water-Level Measuring Point
Surveys 2-16
2.5 Water-Level Data Collection Program 2-16
2.6 Water Sampling and Analysis Program 2-17
2.6.1 Sampling Procedures — 2-18
2.6.2 Analysis Procedures ....— 2-18
2.7 Water Use Along Transects — — —— 2-20
2.7.1 Water Use Along Transects 1n Kill Devil H111 ———-- 2-20
2.7.2 Water Use Along Transects 1n Atlantic Beach/P1ne
Knoll Shores —— —— 2-20
2.7.3 Water Use Along Transects 1n Surf City — 2-25
2.8 Land Use Along Transects — 2-25
2.8.1 Land Use Along Transects 1n Kill Devil Hills 2-30
2.8.2 Land Use Along Transects 1n Atlantic Beach/P1ne
Knoll Shores 2-30
2.8.3 Land Use Along Transcts in Surf (Mty ———— — 2-31
3.0 HYDROGEOLOGIC CHARACTERIZATION OF THE STU0Y AREAS 3-1
3.1 Hydrogeology of the Kill Devil Hills Study Area ————— 3-1
3.1.1 General Hydrogeology ———— 3-1
3.1.2 Hydrogeology of the Shal 1 ow Aquifer —————— 3-1
3.1.2.1 Geologic Setting 3-1
3.1.2.2 Ground-Water Occurrence and Movement 3-4
3.1.2.3 Water Levels — 3-9
3.1.2.4 Net Ground-Water Recharge — 3-11
3.1.2.5 Water Quality — — 3-13
3.1.2.5.1 Relationship Between Freshwater
and Saltwater 3-13
3.1.2.5.2 Effects of Wastewater
Disposal —— 3-18
3.1.3 Summary of Hydrogeologlc Setting for the
Kjll Devil Hills Study Area 3-25
3.2 Hydrogeology of the Atlantic Beach/Pine Knoll Shores
Study Area ————————————— 3-25
3.2.1 General Hydrogeology 3-25
3.2.2. Hydrogeology of the Shal Ton AQutfiif 3-27
3.2.2*1 Geologic Setting ——— 3-27
3.2.2.2 Ground-Water Occurrence and Movement -- — 3-27
3.2.2.3 Water Levels 3-36
3.2.2.4 Net Ground-Water Recharge 3-38
1
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TABLE OF CONTENTS
(continued)
3.2.2.5 Water Quality 3-41
3.2.2.5.1 Relationship Between Freshwater
and Saltwater 3-41
3.2.2.5.2 Effects of Wastewater
Disposal 3-49
3.2.3 Summary of Hydrogeologic Setting for the
Atlantic Beach/Pine Knoll Shores Study Area 3-62
3.3 Hydrogeology of the Surf City Study Area 3-62
3.3.1 General Hydrogeology 3-62
3.3.2 Hydrogeology of the Shallow Sand Aquifer 3-64
3.3.2.1 Geologic Setting 3-64
3.3.2.2 Ground-Water Occurrence and Movement 3-64
3.3.2.3 Water Levels — 3-68
3.3.2.4 Net Ground-Water Recharge 3-70
3.3.2.5 Water Quality 3-73
3.3.2.5.1 Relationship Between Freshwater and
Saltwater 3-73
3.3.2.5.2 Effects of Wastewater Disposal 3-77
3.3.3 Summary of Hydrogeologic Setting for the
Surf City Study Area 3-82
4.0 PROBABLE HYDRQLQGIC IMPACTS ASSOCIATED WITH DEVELOPMENT
ACTIVITIES 4-1
4.1 Ground-Water Levels 4-1
4.1.1 Identification of Predictive Water-Level Model 4-1
4.1.2 Model Calibration 4-3
4.1.3 Model Use For Estimating Changes in Ground-
Water Levels 4-7
4.1.4 Model Use for Planning Purposes 4-9
4.1.5 Water-Table Fluctuations Due to Short-Term
Precipitation Events 4-10
4.1.6 Alternate Approach for Model Calibration 4-13
4.1.7 Other Models 4-16
4.? Ground-Water Quality 4-16
4.2.1 Ammonia , 4-18
4.2.2 Nitrate/Nitrite 4-18
4.2.3 MBAS 4-21
4.2.4 Qrthophosphate 4-21
4.2.5 Fecal Coliform Bacteria 4-21
4.2.6 Variation of Chemical Quality with Depth 4-22
5.0 REFERENCES 5-1
6.0 APPENDICES
APPENDIX A - Well Construction Logs 6-1
APPENDIX B - Lithology Logs 6-55
APPENDIX C - Aquifer Pumping Tests 6-175
APPENDIX D - Elevation Data 6-245
APPENDIX E - Water Level Data 6-253
APPENDIX F - Method for Computation of Porosity 6-317
APPENDIX G - Method for Computation of Percolation 6-323
ii
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LIST OF FIGURES
Figure 1-1 Location map 1-2
Figure 2-1 Well site locations for medium and high population
density transects in Kill Devil Hills 2-2
Figure 2-2 Well site locations for low population density
transect in Kill Devil Hills — 2-3
Figure 2-3 Well site locations for high population density
transects in Atlantic Beach —-——— 2-4
Figure 2-4 Well site locations for medium and low population
density transects in Pine Knoll Shores 2-5
Figure 2-5 Well site locations for medium and high population
density transects in Surf City —— ——— 2-7
Figure 2-6 Water use along transects in Kill Devil Hills — 2-22
Figure 2-7 Water use along transects in Atlantic Beach 2-26
Figure 2-8 Water use along transects in Pine Knoll Shores —— 2-27
Figure 2-9 Water use along transects in Surf City — 2-29
Figure 3-1 Generalized hydrogeologlc cross-section for
Bodie Island 3*2
Figure 3-2 Hydrogeologic cross-sections for the shallow
aquifer at Kill Devil Hills — 3-3
Figure 3-3 Ground-water flowpaths 1n the shallow acjalffer
at Kill Devil Hills on August 17, 1984 3-5
Figure 3-4 Ground-water flowpaths 1n the shallow aquifer
at Kill Devil Hills on February 9, 1985 3-6
Figure 3-5 Ground-water flowpaths in the shallow aquifer
at Kill Devil Hills on October 20, 1984 3-7
Figure 3-6 Relation between ground-water levels and
precipitation in the Kill Devil Htlls study area 3-10
Figure 3-7 Variation in total dissolved solids concentration
along Transect K2 3-19
Figure 3-8 Variation in.nitrate plus nitrite concentration
along Transect K2 — 3-20
Figure 3-9 Variation in ammtmla concentration •)an« Transect
K2 3-21
Figure 3-10 Variation in orthophosphate concentration along
Transect K2 3-22
ill
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LIST OF FIGURES
(continued)
Figure 3-11 Variation in MBAS concentration along Transect
K2 3-24
Figure 3-12 Generalized hydrogeologic cross-section for
Bogue Banks 3-26
Figure 3-13 Hydrogeologic cross-sections for the shallow aquifer
at Atlantic Beach i 3-28
Figure 3-14 Hydrogeologic cross-sections for the shallow aquifer
at Pine Knoll Shores 3-29
Figure 3-15 Ground-water flowpaths in the shallow aquifer at
Atlantic Beach on August 19, 1984 — 3-30
Figure 3-16 Ground-water flowpaths in the shallow aquifer at
Pine Knoll Shores on August 19, 1984 3-31
Figure 3-17 Ground-water flowpaths in the shallow aquifer at
Atlantic Beach on February 11, 1985 3-32
Figure 3-18 Ground-water flowpaths in the shallow aquifer at
Pine Knoll Shores on February 11, 1985 3-33
Figure 3-19 Relation between ground-water levels and preci-
pitation in the Atlantic Beach/Pine Knoll Shores
study area 3-37
Figure 3-20 Variation in total dissolved solids concentration
along Transect A1 3-47
Figure 3-21 Variation in total dissolved solids concentration
along Transect A2 3-48
Figure 3-22 Variation in nitrate plus nitrite concentration
along Transect A1 3-50
Figure 3-23 Variation in nitrate plus nitrite concentration
along Transect A2 ' 3-51
Figure 3-24 Variation in ammonia concentration along
Transect A1 3-52
Figure 3-25 Variation in ammonia concentration along
Transect A2 3-53
Fiqure 3-26 Variation in orthophosphate concentration along
Transect A1 — 3-55
Figure 3-27 Variation in orthophosphate concentration along
Transect A2 3-56
Figure 3-28 Variation in MBAS concentration along Transect A1 — 3-57
iv
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LIST OF FIGURES
(continued)
Figure 3-29 Variation in MBAS concentration along
Transect A2 3-58
Figure 3-30 Variation in fecal coliform concentration along
Transect A1 3-59
Figure 3-31 Variation in fecal coliform concentration along
Transect A2 3-60
Figure 3-32 Generalized hydrogeologic cross-section for the
Surf City study area 3-63
Figure 3-33 Hydrogeologic cross-sections for the shallow sand
aquifer at Surf City —-—-— — 3-65
Figure 3-34 Generalized flow directions in the shallow sand
aquifer at Surf City on August 22, 1984 3-66
Figure 3-35 Generalized flow directions in the shallow sand
aquifer at Surf City on February 12-13, 1985 3-67
Figure 3-36 Relation between ground-water levels and
precipitation in the Surf City study area 3-71
Figure 3-37 Variation in total dissolved solids concentration
along Transect S3 — — 3-76
Figure 3-38 Variation in nitrate plus nitrite concentration
along Transect S3 3-78
Figure 3-39 Variation in ammonia concentration along
Transect S3 3-79
Figure 3-40 Variation in orthophosphate concentration
along Transect S3 3-80
Figure 3-41 Variation in MBAS concentration along
Transect S3 3-81
Figure 4-1 Simplified model for the shallow aquifer 4-2
Figure 4-2 Flow chart for computing water-table elevations — 4-12
Figure 4-3 Comparison between wastewater disposal rate
and mean concentration 1n water of selected
compounds —— 4-20
v
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LIST OF TABLES
Table 2-1 Summary of transect lengths 2-8
Table 2-2 Summary of monitoring well construction 2-9
Table 2-3 Summary of aquifer pumping test results 2-14
Table 2-4 Summary of sample preservation and analytical
analysis methods 2-1
Table 2-5 Summary of water usage along transects in
Kill Devil Hills - 2-21
Table 2-6 Summary of water usage along transects in
Atlantic Beach 2-23
Table 2-7 Summary of water usage along transects in
Pine Knoll Shores 2-24
Table 2-8 Summary of water usage along transects in
Surf City 2"28
Table 3-1 Ground-water flow velocities and travel times
along transects in Kill Devil Hills 3-8
Table 3-2 Summary of recharge computations for transects
in Kill Devil Hills 3-12
Table 3-3 Summary of ground-water quality analyses for
Kill Devil Hills . 3-14
Table 3-4 Ground-water flow velocities and travel times
along transects in Atlantic Beach and
Pine Knoll Shores 3-35
Table 3-5 Summary of recharge computations for transects in
Atlantic Beach 3-39
Table 3-6 Summary of recharge computations for transects in
Pine Knoll Shores 3-40
Table 3-7 Summary of ground-water quality analyses for
Atlantic Beach/Pine Knoll Shores 3-42
Table 3-8 Ground-water flow veolocities and travel times
along transects in Surf City 3-69
Table 3-9 Summary of recharge computations for transects in
Surf City 3-72
Table 3-10 Summary of ground-water analyses for Surf City 3-74
Table 4-1 Comparison between measured and apparent hydraulic
conductivities 4-5
vi
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LIST OF TABLES
(continued)
Table 4-2 Computed and observed water-table elevations
along transects 4_6
Table 4-3 Computed average water-table elevations at
center of transects with and without wastewater
disposal 4-8
Table 4-4 Impacts on water levels of proposed development
for hypothetical case 4-11
Table 4-5 Water-table rise associated with various rainfall
intensities 4-14
Table 4-6 Comparison between measured and apparent
hydraulic conductivities and island half-widths 4-15
Table 4-7 Computed ana observed water-table elevations
along transects using an alternate approach 4-17
Table 4-8 Mean concentrations in ground water of
selected compounds 4-19
Table 4-9 Variation of chemical quality with depth - 4-23
vii
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EXECUTIVE SUMMARY
A critical factor to the continued population growth on the barrier
islands along the coast of North Carolina is the impacts of wastewater
disposal on ground-water levels and ground-water quality. Residents on
the islands generally receive their water supply from the mainland or
from deep wells on the islands. On-site systems are used to treat and
dispose of the wastewater. This process results in a net addition of
water to the shallowest aquifer underlying the islands.
Monitoring wells were constructed in the communities of Kill Devil
Hills, Atlantic Beach, Pine Knoll Shores and Surf City to aid in defining
the shallow subsurface hydrogeology of the barrier islands and to esti-
mate the impacts of wastewater disposal on ground-water levels and water
quality. Wells were completed along transects that were generally per-
pendicular to the ocean beach and extended across the width of the
islands. The transect locations were chosen to reflect variations in
population density. Hydrogeologic data obtained from the wells included
1 ithologic data collected during drilling of the wells plus water level
and water quality data collected during periodic visits to the islands.
Shallow subsurface conditions are similar in each of the areas
studied. The shallow aquifer consists of fine to medium sands with
interbedded silty sands that are underlain by beds of silt and clay. The
silt and clay beds restrict the downward movement of water and in this
sense promote the lateral movement of water toward the ocean and sound.
Ground-water movement in the shallow aquifer is generally away from
the central part of the islands in each study area. Average flow veloci-
ties along transects varied from less than 0.1 to about 1.6 feet per day.
Travel times from the center of the islands to discharge points along the
ocean and sound, which are dependent upon the half-width of the island
and the flow velocity, varied from as little as one year at Atlantic
Beach to possibly decades at Pine Knoll Shores.
Accretion of water to the shallow aquifer in each study area comes
from precipitation and wastewater disposal. Precipitation accounted for
86 percent or more of the water gain, or recharge, received along tran-
sects in Kill Devil Hills and Pine Knoll Shores, 70 percent of the
recharge received along transects in Atlantic Beach, and 78 percent or
more of the recharge received along Transects in Surf City during the
study period. Wastewater disposal accounted for the remainder of the
recharge received along the transects.
~ u elevations in the Kill Devil Hills and Atlantic
Beach/Pine Knoll Shores study areas varied similarly in response to
recharge and discharge. Water levels would rise rapidly in response to
precipitation and fall gradually at other times due to evapotranspiration
and seepage of water to the ocean and sound. The observed long-term
water-level recession rate due to natural discharge is about 0.03 feet
per day in both areas. The influence of tidal fluctuations on water
levels appears to be confined to areas adjacent to the ocean and sound.
1
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Water-table elevations in the Surf City area were influenced by
tidal fluctuations as well as by precipitation and discharge. Water
levels rose and fell twice daily in response to tidal fluctuations.
These fluctuations were superimposed upon broader fluctuations that
varied with recharge and discharge. Water levels would rise rapidly in
response to precipitation and fall gradually at other times due to
natural discharge. The observed long-term water-level recession rate due
to natural discharge is about 0.06 ft/day.
The shallow aquifers at Kill Devil Hills, Atlantic Beach and Pine
Knoll Shores generally contained freshwater. Minor intrusions of
brackish water were observed near the ocean at Transects K1 and K2 in
Kill Devil Hills. Some brackish water was noted at Transect P2 in Pine
Knoll Shores near the ocean and near Bogue Sound. In Atlantic Beach,
brackish water generally existed in the confining beds underlying the
shallow aquifer.
The shallow aquifer at Surf City contains a lens of freshwater
underlain by brackish to saline water. This freshwater lens probably
extends to a maximum depth of about 10 feet, which occurs at the center
of the island.
The disposal of wastewater has had a minor impact on water quality
in the shallow aquifers at Kill Devil Hills and Surf City. Nitrate/
nitrite were detected in ground-water samples but never exceeded drinking
water standards. MBAS levels above secondary drinking water standards
were noted in only one ground-water sample from Kill Devil Hills and in
none from Surf City. Fecal coliform were noted in two of 100 water
samples taken from wells in Kill Devil Hills and in 10 of 61 water
samples taken from wells in Surf City. Eight of the 10 water samples
from Surf City with fecal coliform present were either one or two col/100
ml. The fecal coliform generally occurred in the summer or fall of 1984.
Wastewater disposal has had some impact on water quality in the
shallow aquifer in the Atlantic Beach/Pine Knoll Shores study area.
Extreme variations in fecal coliform were noted in water from some well
sites. Intrusion of surface runoff into the wells at those sites is
believed to be responsible for the fecal coliform in the wells. However,
fecal coliform were also noted in water from some of the other well sites
in the study area. These were generally detected in July 1984 and not
detected at other times, although a few exceptions can be noted.
Nitrate/nitrite and MBAS, although detected in water samples, did not
exceed drinking water standards.
Wastewater disposal has resulted i/i increased water levels in each
of the study areas. The largest increase, approximately one foot, has
occurred at Atlantic Beach. The least impact, between 0.1 and 0.4 feet,
has occurred at Pine Knoll Shores. A simple analytical model that was
identified as a part of this study was used to compute these impacts.
There is no apparent correlation between the amount of wastewater
disposal and the distribution of wastewater contaminants in the ground
water except for fecal coliform bacteria.
2
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1.0 INTRODUCTION
The barrier islands are a narrow chain of islands along the coast
of North Carolina. These islands have a total length of approximately
260 miles. Island widths are typically 2,000 feet, but vary from less
than 500 feet to more than two miles. Altitudes range from sea level to
greater than 100 feet but are generally less than 20 feet.
Three areas on these islands have been studied. The first area is
Kill Devil Hills on Bodie Island. The second area includes Atlantic
Beach and Pine Knoll Shores on Bogue Banks. The third area is Surf City,
on Topsail Island. The study area locations are shown in Figure 1-1.
Residents in the study areas generally receive their water supply
from the mainland or from deep wells on the islands. Water is distri-
buted to individual homes through municipal water supply distribution
systems.
Some residents obtain their water supply from shallow wells. These
wells withdraw water from the water table aquifer that directly underlies
the islands.
All residents on the islands use on-site systems to treat and
dispose of their wastewater. These systems generally consist of a
package plant treatment system for multi-resident buildings and indivi-
dual septic systems for private residences. A drain field is used in
either case to dispose of the treated wastewater by infiltration of the
water into the ground.
The U.S. Environmental Protection Agency (EPA) is actively involved
in investigating alternate technologies that may be applied to wastewater
management on the North Carolina barrier islands. As a part of these
investigations, the EPA prepared an Environmental Impact Statement that
identified the need for estimating the impacts of present wastewater
treatment and disposal practices on the environment of the islands
(USEPA, 1983). The impacts identified by the EPA as having the greatest
significance include increases in ground-water levels associated with the
percolation of wastewater to the water table and changes in ground-water
quality resulting from the addition of wastewater to the ground-water
system.
1.1 Study Objectives
This study addresses those objectives defined in the EPA North
Carolina Barrier Islands Environmental Impact Statement (USEPA, 1983).
One objective is to develop a simple model for computing ground-water
level changes caused by disposal of wastewater to the shallow aquifer
system. A second objective is to estimate the impact of the wastewater
disposal on ground-water quality.
1-1
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enlarged area
_ VIRGINIA
NORTH CAROLINA
Kill Devil Hills
Study Area
ATLANTIC OCEAN
Atlantic Beach/Pine
Knoll Shores Study Area
fO
Wilmington
Surf City
Study Area
0 10 20 30mile$
Figure 1-1. Location map.
1-2
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1.2 Approach
Monitoring wells were constructed in each of the study areas along
transects that were generally perpendicular to the ocean beach. Each
transect extended across the width of the island. The transect locations
in each study area were chosen to reflect variations in population
density.
Hydrogeologic data were collected froin the wells along each tran-
sect during the course of the study. The boreholes that were drilled for
the wells were used to collect lithologic data to aid in defining the
near-surface geology underlying each study area. Water-level data were
collected periodically to aid in defining the relation between lithology
and ground-water levels and to aid in estimating the impact of wastewater
dipsosal on water levels. Water samples for chemical analyses were
collected periodically to aid in defining the impact of wastewater dis-
posal on water quality.
1-3
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2.0 HYDR0L06IC FIELD DATA COLLECTION PROGRAM
The hydrologic field data collection program included installing
monitoring wells and tidal gauges, conducting aquifer pumping tests and
periodically collecting water level data and water samples for chemical
analyses. These data were collected to aid in determining a hydrologic
budget for each study area, to define the hydrogeology underlying each
study area and to estimate the impacts of current wastewater disposal
practices on the hydrogeology of the study areas.
Land and water use data were collected for each transect to aid in
estimating wastewater disposal along the transects.
2.1 Installation of Monitoring Hells
One hundred temporary monitoring wells were constructed in the
three study areas. Forty-one wells were constructed in the Kill Devil
Hills study area, 42 in the Atlantic Beach/Pine Knoll Shores study area,
and 17 in the Surf City study area.
2.1.1 Transect Locations
The wells in each study area were located along transect lines that
extended across the width of the island. Transect lines were chosen to
reflect variations in population density.
Tentative transect locations were identified during reconnaissance
visits to the study areas. High population density, medium population
density and low population density transects were identified, with the
terms high, medium and low based on a visual impression of the relative
degree of development along the transects. Transect locations were fina-
lized through discussions with local officials.
Three transect lines were located in the Kill Devil Hills study
area (Figures 2-1 and 2-2). One line, Transect Kl, was located along
Chowan Avenue in an area with a medium population density. A second
line, Transect K2, was located along Fifth Avenue in an area with a high
population density. A third line, Transect K3, was located immediately
south of the Kitty Hawk Memorial in an area of relatively low population.
Four transect lines were located in the Atlantic Beach/Pine Knoll
Shores study area. One line, Transect Al, was located along Dunes Avenue
in Atlantic Beach. A second line, Transect A2, was located along Brooks
Street and Wilson Avenue in Atlantic Beach. Both of these transects are
in areas of high population density. A third line, Transect PI, was
located along Yaupon Road in Pine Knoll Shores in an area with a medium
population density. A fourth line, Transect P2, was located along Pine
Knoll Boulevard in Pine Knoll Shores in an area with a low population
density. The locations of the transects in Atlantic Beach and Pine Knoll
Shores are shown in Figures 2-3 and 2-4, respectively.
2-1
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NJ
I
to
EXPLANATION
A®Well Site and Identification
2000
Figure 2-1
Well site locations for medium and high population
density transects in Kill Devil Hills.
FEET
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JO
I
u>
ATLANTIC OCEAN
Figure 2-2. Well site locations for low population density transect in Kill Devil Hills.
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EXPLANATION 0 250 500 1000 2000
I 1 2 -J- 1
A® Well Site and Identification FEET
Figure 2-3. Well site locations for high population density
transects in Atlantic Beach.
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to
I
U1
Pine
Knoll
Blvd.
BOGUE SOUND
Yaupon Rd.
N
/
I
.B J
z
fcr; ¦'
¦y Igf1*''
ATLANTIC OCEAN
EXPLANATION
A® Well Site and Identification
500 1000
—I I
2000
FEET
Figure 2-4. Well site locations for medium and low population density
transects in Pine Knoll Shores.
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Two transect lines were located in the Surf City study area (Figure
2-5). One line, Transect SI, was located along Pender Avenue in an area
with a medium population density. The second line, Transect S3, was
located along Goldsboro Avenue in an area of relatively high population.
Wells were not constructed in an area of low population density in
Surf City. Alternate low population density transect lines were iden-
tified but permission to construct wells along these transects could not
be obtained from the residents.
Transect length, or island width, varied within a study area and
between study areas. Transect lengths are summarized in Table 2-1.
2.1.2 Well Sites and Mel! Construction
Well sites were spaced along each transect with one site located
near the ocean, one site located near the sound and generally one or more
sites located at approximately equal intervals between the ocean and
sound sites (see Figures 2-1 through 2-5).
Multiple wells were completed at many of the well sites. Each
ocean and sound site has multiple wells as does each site at the mid-
point in a transect. Additionally, all sites along the high population
density transects were completed with multiple wells. Monitoring well
construction at each site is summarized in Table 2-2. Detailed construc-
tion records for each well site are presented in Appendix A.
Sites with multiple monitoring wells have each well completed at a
different depth. One well is completed near the water table surface. A
second well is generally completed midway between the water table surface
and the top of clayey confining beds that form the base of the shallow
aquifer. A third well is completed immediately above the top of the con-
fining beds. At some transects, the midpoint well site has a fourth well
completed immediately below the clayey confining beds.
Borings for the monitoring wells were drilled in one of two ways.
Borings with a total depth of less than about 20 feet were generally
advanced using a hollow stem auger. Deeper borings were generally
drilled using mud rotary techniques. The borehole for each well was
drilled large enough to assure a two-inch clearance between the borehole
wall and the well pipe.
Most borings were completed as two-inch diameter monitoring wells
(see Table 2-2). These wells were constructed using schedule 40 PVC pipe
and screen. The screen slot size was generally 0.010 inches and the
screen length was generally five feet. Bentonite or cement urout was
used to fill the annul us between the borehole and the well pipe in areas
where confining layers were penetrated by the borehole. The bnrehnle was
generally allowed to collapse against tt£ well pipe ^otier a?ea i? Me
hole. The we Is were finished at land surface using steel protector
pipes with locking caps. The protector pipes were set in a cement or
bentonite surface seal.
2-6
-------
INTRACOASTAL WATERWAY
I
-J
v<#~
h
Goldsboro Ave.
M o C
¦ z&ib
o <*>
& *
m "» '*¦*-»-» - >¦
^ „ Jtefe W's»«»&sls
"Nfe
' :v?;. "*1
ATLANTIC
OCEAN
|Ski% i*?'
Pender Ave
'
EXPLANATION
A® Well Site and Identification
Figure 2-5.
o 590 1000
FEET
2000
Well site locations for medium and high population
density transects in Surf City.
-------
TABLE 2-1
SUMMARY OF TRANSECT LENGTHS
Transect
location
Transect
ID
Transect
length
(ft)
Kill Devil Hills
K1
4,120
K2
4,920
K3
7,800
Atlantic Beach
A1
1,310
A2
1,800
Pine Knoll Shores
PI
2,930
P2
3,920
Surf City
SI
600
S3
875
2-8
-------
TABLE 2-2
SUMMARY OF MONITORING WELL CONSTRUCTION
Well
10(1)
Depth of
borehole
(ft)
Depth to
bottom of
screen
(ft)
Screen
length
(ft)
Well
diameter
(inches)
KILL DEVIL
HILLS
Transect K1
K1A1
15.0
13.0
5
K1A2
40.5
40.3
5
K1A3
86.5
70.0
5
K1B1
12.0
10.0
5
K1C1
13.0
11.0
5
K1C4
40.0
36.0
5
K1C5
86.5
61.1
5
K1D1
13.0
11.0
5
K1E1
12.0
9.0
5
K1E2
40.0
39.3
5
K1E3
96.5
64.0
5
Transect K2
K2AI
16.0
14.0
5
K2A2
46.0
45.8
5
K2A3
110.0
95.0
5
K2BI
10.0
10.0
5
K2B2
40.0
39.7
5
K2B3
81.5
75.0
5
K2C1
10.0
10.0
5
K2C2
41.1
39.0
5
K2C3
91.5
80.0
5
K2C4
120.0
100.0
5
K2D1
12.0
11.0
5
K2D2
40.0
39.0
5
K2D3
85.0
76.0
5
K2E1
9.0
9.0
5
K2E2
40.5
40.3
5
K2E3
86.5
78.0
5
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
2-9
-------
SUMMARY OF
TABLE 2-2
(continued)
MONITORING WELL
CONSTRUCTION
Wei 1 Depth of
ID(1) borehole
(ft)
Depth to
bottom of
screen
(ft)
Screen
1ength
(ft)
Well
diameter
(inches)
KILL DEVIL HILLS (cont'd)
Transect K3
K3A1 14.0
K3A2 40.0
K3A2B 61.0
K3A3B 106.5
14.0
39.4
60.0
98.0
5
5
5
5
2
2
2
2
K3B1 9.0
9.0
5
2
K3C1 9.0
9.0
5
2
K3D1 13.6
K3D2 47.0
K3D3B 86.5
13.0
46.5
79.0
5
20
5
6
4
2
K3E1 10.0
9.5
5
2
K3F1 12.0
11.0
5
2
K3G1 15.0
K3G2 41.5
K3G3 87.0
9.4
39.5
75.0
5
5
5
2
2
2
ATLANTIC BEACH
Transect A1
A1A1 15.0
A1A3 50.0
11.0
42.0
5
5
2
2
A1B1 13.0
A1B3 42.0
11.0
35.0
5
5
2
2
A1C1 15.0
A1C3 37.0
11.0
32.0
5
5
2
2
A1D1 20.0
A1D2 52.0
A1D3 110.0
13.0
40.0
96.0
5
5
5
2
2
2
Transect A2
A2A1 15.0
A2A3 41.5
A2A4 70.0
13.5
32.0
67.9
5
5
5
2
2
2
2-10
-------
TABLE 2-2
(continued)
SUMMARY OF MONITORING WELL CONSTRUCTION
Well
IDU)
Depth of
borehole
(ft)
Depth to
bottom of
screen
(ft)
Screen
length
(ft)
Well
di ameter
(inches)
Atlantic Beach (cont'd)
Transect A2 (cont'd)
A2B1
A2B3
A2B4
12.0
37.0
165.0
9.7
30.0
90.0
5
5
5
2
2
2
A2C1
A2C3
A2C4
13.0
31.5
75.0
11.0
22.0
70.0
5
5
5
2
2
2
PINE KNOLL
Transect PI
SHORES
P1A1
P1A2
P1A3
21.0
45.0
66.5
17.0
40.0
60.0
5
5
5
2
2
2
P1B1
19.0
16.6
5
2
P1C1
P1C2
P1C3
P1C4
13.0
35.0
66.5
79.0
12.0
33.0
55.8
73.0
5
5
5
5
2
2
2
2
P1D1
15.0
15.0
5
2
P1E1
P1E2
P1E3
15.0
35.0
61.5
12.0
34.0
56.0
5
5
5
2
2
2
Transect P2
P2A1
P2A2
P2A3
20.0
40.0
67.0
19.0
36.7
60.0
5
5
5
2
2
2
P2B1
16.5
14.0
5
2
P2C1
P2C2
P2C3
P2C4
13.0
35.0
51.5
75.0
10.6
30.0
37.0
69.5
5
15
5
5
6
4
2
2
P2D1
15.0
14.0
5
2
P2E1
P2E2
P2E3
15.0
30.0
51.5
13.0
27.0
42.0
2-11
5
5
5
2
-------
SUMMARY
TABLE 2-2
(continued)
OF MONITORING WELL
CONSTRUCTION
Well
idU)
Depth of
borehol e
(ft)
Depth to
bottom of
screen
(ft)
Screen
1ength
(ft)
Well
diameter
(inches)
SURF CITY
Transect SI
S1A1
15.0
14.7
5
2
S1A2
41.0
37.0
5
2
S1A3
60.0
60.0
5
2
S1B1
16.0
11.0
5
2
S1B2
33.0
31.0
5
2
S1B3
70.0
70.0
5
2
Transect S3
S3A1
20.0
17.4
5
2
S3A2
34.0
31.0
4.5
2
S3A3
70.0
65.0
5
2
S381
18.0
14.2
5.6
6
S3B2
30.0
29.8
5
2
S3B3
52.0
48.6
5
2
S3B4
135.0
124.0
5
2
S3B5
31.5
28.4
4.2
4
S3C1
16.0
11.0
5
2
S3C2
30.0
27.0
5
2
S3C3
80.0
70.0
5
2
Each well is identified by transect, well site and a sequence number.
The first two characters of the well number identify the transect.
The third character identifies the well site location within the
transect. The remaining characters identify the individual well at
the well site.
2-12
-------
One borehole in each study area was completed as a four-inch
diameter monitoring well (see Table 2-2). These wells were constructed
to serve as the pumped wells for conducting aquifer pumping tests.
One borehole' in each study area was completed as a six-inch
diameter monitoring well (see Table 2-2). A water-level recorder was
installed over each of these wells to collect a continuous record of
water-table fluctuations in the study areas.
The larger diameter monitoring wells were completed in a manner
similar to the two-inch diameter wells. Schedule 40 PVC pipe and screen
were used to construct these wells and the wells were finished at land
surface using steel protector pipes with locking caps. The protector
pipes were set in a cement or bentonite surface seal.
A lithologic sampling record was completed for each well site by a
geologist who monitored drilling activities at the site. The record was
constructed using split-spoon samples taken from one or more of the bore-
holes drilled at the site, supplemented by an examination of cuttings
during drilling operations. A lithologic sampling record for each well
site is presented in Appendix B.
Each monitoring well was developed by pumping. Water was pumped
from the well until the well produced sediment-free water, or for a mini-
mum of one hour, if clear sediment-free water was produced in less time.
2.2 Installation of Tidal Gauges
Two tidal gauges were installed in each study area. One tidal
gauge was established in the sound and one tidal gauge was established in
the ocean. The ocean tidal gauges consisted of two-inch diameter PVC
pipes with locking caps that were attached to ocean fishing piers. The
sound tidal gauges were metal staff gauges graduated in 0.02-foot inter-
vals that were attached to piers in the sounds.
2.3 Aquifer Testing
An aquifer pumping test was conducted in each study area to collect
data that could be used to determine the hydraulic properties of the
shallow aquifer in that area. These tests included pumping a constant
volume of water from the test well and generally measuring water levels
in the test well and nearby wells during pumping and for approximately
two hours after pumping stopped.
The water-level data collected during testing were used to compute
the hydraulic properties of the aquifer systems. The modified Theis
nonequilibrium formula (Ferris et al., 1962), the Theis recovery formula
(Ferris et al., 1962), and procedures developed by Stallman for eva-
luating test data from partially penetrating wells in unconfined aquifers
(Lohman, 1972) were used for the computations. The aquifer pumping test
results are summarized in Table 2-3. A detailed description of each test
is presented in Appendix C.
2-13
-------
TABLE 2-3
SUMMARY OF AQUIFER PULPING TEST RESULTS
Location
Well
Transmissivity
(gpd/ft)
Horizontal
hydraulic
conductivity
(gpd/ft2)
Vertical
hydraulic
conductivity
(gpd/ft2)
Storage
coefficient
Specific
storage
(1/ft)
Method of analysis
Kill Devil Hills
K302
K3D2
11,100
10,700
555
535
-
-
-
Modified Theis nonequilibrium
Theis recovery
AVG.
10,900
545
Pine Knoll Shores
P2C2
P2C2
13,300
17,800
377
504
-
-
-
Modified Theis nonequilibrium
Theis recovery
P2C3
13,000
366
-
4.5x10_<*
1.3x10"5
Modified Theis nonequilibrium
P2C3
19,000
535
-
-
Theis recovery
AVG.
16,600
46 8
4.5x10~"
1.3x10~5
Surf City
S3B2
25,100
930
-
-
-
Modified Theis nonequilibrium
S3B5
11,900
441
-
2.0x10"2
0.7x10"3
Partially penetrating well
S3B1
13,700
507
497
4.7x10-2
1.7x10-3
Partially penetrating well
AVG.
16,900
626
497
3.8x10-2
1.4x10"
-------
^•le ProPer^ °f the shallow aquifers of greatest interest in this
study is hydraulic conductivity. This property is a measure of an
aquirer s capacity to transmit water and is the same whether the aquifer
in an unconfined or confined condition. The hydraulic conductivity of
an aquifer must be known before time independent problems involving
ground-water flow can be solved.
The hydraulic conductivities of the shallow aquifer systems at the
t8St- !^es are relatively uniform. The hydraulic conductivity
! ii clan gallons per day per square foot (gpd/ft^) at Pine
Knoll Shores to 626 gpd/ft' at Surf City. These values are typical of
those for a fairly clean sand (Freeze and Cherry, 1979) and were esti-
mated by dividing the computed transmissivities in each area by the esti-
mated effective saturated thickness of the shallow aquifer during the
test period.
The specific storage of an aquifer is another property generally of
interest in ground-water studies. Specific storage is defined as the
volume of water the aquifer releases from or takes into storage per unit
volume of aquifer under a unit change in head within the aquifer. The
specific storage for an aquifer depends upon the degree to which the
aquifer is confined. This parameter, as well as hydraulic conductivity,
must be known before time dependent problems involving ground-water flow
can be solved.
The specific storage of the shallow aquifer in Pine Knoll Shores
indicates that this aquifer is relatively confined in the vicinity of
testing. The specific storage for the shallow aquifer is 1.3 x
ft i (Table 2-3). A specific storage value of about 1 x
10" ft" would indicate a fully confined condition (Lohman, 1972),
whereas a value of 1 x 10"^ to 1 x 10"^ ft"* would probably indicate an
unconfined condition. The specific storage was computed by dividing the
storage coefficient determined from testing by the estimated effective
saturated thickness of the aquifer during testing.
t Ihe specific storage of the shallow aquifer for Surf City indicates
that the aquifer is relatively unconfined at that test site. The speci-
fic storage of the shallow aquifer there is about 1.4 x 10 ft (Table
2-3).
Water-level observations during testing at Kill Devil Hills indi-
cated that the shallow aquifer system there was at least partially con-
fined in the vicinity of the test.
Localized layers of organic silt near land surface are responsible
for the confinement observed at the aquifer pumping test sites in Kill
Devil Hills and Pine Knoll Shores. One- to two-foot layers of organic
silt were encountered at shallow depths at both sites. Near-surface
organic silt layers were also encountered at some of the other well sites
in the Kill Devil Hills and Atlantic Beach/Pine Knoll Shores study areas.
2-15
-------
Bailing tests were performed at some well sites in an attempt to
gain added information about the hydraulic properties of the shallow
aquifer. The data obtained from these tests could not be interpreted
with confidence and were not used. The bailing test method was developed
for testing in confined aquifer systems and has limited usefulness in
unconfined aquifers (Lohman, 1972).
2.4 Transect Profile and Water-Level Measuring Point Surveys
The land surface profile along each transect, referenced to mean
sea level (MSL), was determined by differential surveying. This infor-
mation was needed to define the relationship between land surface and the
ground-water table along the transects.
The elevation of the water-level measuring point on each monitoring
well and ocean tidal gauge was surveyed at the time of the topographic
survey. These elevations were determined to the nearest 0.01 foot of
elevation. They are used to convert depth to water measurements to
equivalent mean sea level elevations.
The zero elevation for each sound tidal gauge, referenced to mean
sea level, was also surveyed at the time of the topographic survey.
These elevations were also determined to the nearest 0.01 foot of eleva-
tion. This information is needed to convert staff gauge readings to
equivalent mean sea level elevations.
The mean sea level elevations for each monitoring well measuring
point, for each ocean tidal gauge measuring point, and for the zero
reading of each 90und tidal gauge are tabulated in Appendix D.
Temporary bench marks were established in the vicinity of each well
site and each tidal gauge. These bench marks are for providing reference
elevations for replacing well casings or tidal gauges that might become
damaged during the course of the study. Descriptions of each bench mark
and its elevation are summarized in Appendix D.
2.5 Water-Level Data Collection Program
The depth to ground water in each monitoring well, referenced to
the water-level measuring point on the well, was determined during
monthly visits to the study areas. These measurements were made with a
steel tape, except for the 11 November 1984 measurements in Atlantic
Beach and Pine Knoll Shores, which were made with an electric water-level
indicator. All of the water-level measurements were made to the nearest
0.01 foot.
Ocean and sound water levels were generally measured during monthly
visits to the study areas. Ocean water levels were measured to the
nearest 0.01 foot using a steel tape. Sound water levels were read to
the nearest 0.01 foot directly from the staff gauge.
2-16
-------
The "wetted tape" method was used to determine the depth to water
when a steel tape was used for the measurement. This method involved
chalking the lower portion of the tape, lowering a known length of tape
into the monitoring well or tidal gauge stilling pipe, then retrieving
the tape and noting the length of tape that had been wetted. The chalk
aids in defining the wetted portion of the tape. The depth to water is
the difference between the length of tape placed in the well and the
length of wetted tape. The tape length lowered into the well is measured
from the designated water-level measuring point for the well.
The electric water-level indicator (electric tape) used for some of
the measurements reads directly the depth to water from the measuring
point. The electric tape and steel tape used during the project have
been checked against each other and found to agree within 0.01 foot.
Two complete sets of ground-water level measuranents were generally
taken at each monitoring well during a monthly visit. The normal field
procedure included measuring water levels at the ocean and sound tidal
gauges, then taking a complete set of ground-water level measurements
along one or more of the transects in the study area, then taking another
complete set of ground-water level measurements along the same transects,
and then taking a final set of measurements at the ocean and sound tidal
gauges. In this manner, the ground-water level measurements along a
transect, together with the ocean and sound tidal measurements, could be
referenced to a common instant in time.
Diurnal ground-water level fluctuations were investigated in each
study area. Ground-water levels, together with ocean and sound water
levels, were measured periodically over a 24-hour period in August 1984
and again in February 1985.
Tidal tables (NOAA, 1985) were used to compute ocean water levels
to supplement measurements taken in the field. The ocean tidal guages
occasionally would be inaccessible due to inclement weather. Also, the
ocean tidal guages at Kill Devil Hills and Surf City were damayed by
storms before the study was completed.
Ground-water level measurements and tidal measurements taken during
the course of the study are summarized in Appendix E.
2.6 Mater Sampling and Analysis Program
Ground-water quality was sampled periodically in each of the study
areas. Water quality was sampled every three months along the high popu-
lation density transects, once in the summer and once in the winter along
the medium population density transects, and once in the winter along the
low population density transects. The results of this sampling are pre-
sented in Section 3.
Additional sampling was done in the Atlantic Beach/Pine Knoll
Shores study area in September 1984 immediately following hurricane Diane
(see Section 3). The high population density transects were sampled to
aid in defining the impact of a major storm event on ground-water
quality.
2-17
-------
Some water quality characteristics were determined from field
measurements while others were determined from laboratory measurements of
water samples taken 1n the field. The parameters measured 1n the field
Included pH, temperature, fecal coHform bacteria and specific conduc-
tance. Those measured 1n the laboratory Included ammonia, nitrate/
nitrite, chloride, sodium, total dissolved solids, orthophosphate, MBAS
(methylene blue active substances), alkalinity and hardness. MBAS is a
compound used in detergents and is not found naturally in the environ-
ment.
2.6.1 Sampling Procedures
Each well was purged before sampling by removing a minimum of three
volumes of water from the well casing. The deep wells were generally
purged using a centrifugal pump and the shallow wells were generally
purged using a PVC bailer. The volume of water that needed to be removed
was determined from depth to water measurements made prior to sampling
and from well construction records.
Water samples for laboratory analyses were collected and preserved
after the well had been purged. A peristaltic pump was used to draw
water from the well and into sample containers. The types of sample con-
tainers and preservation techniques used 1n conjunction with sampling are
summarized in Table 2-4.
The equipment used for purging and sampling the wells was decon-
taminated prior to its use at each well. The suction hose for the
centrifugal pump and the PVC bailer were rinsed with distilled water
prior to their use for purging the wells. The teflon tubing used with
the peristaltic pump was also rinsed with distilled water and approxi-
mately 200 milliliters of distilled water was pumped through the hose
prior to sampling each well. This decontamination procedure was con-
sidered adequate for the types of water analyses that were being per-
formed.
Sample holding times were minimized by shipping the water samples
to the chemistry laboratory at the end of each work day. The water
samples were packaged 1n 1ce chests as they were collected. At the end
of each day, these chests were sealed and taken to the nearest airport
with overnight delivery service to Atlanta, Georgia. The chests would be
flown to Atlanta 1n the evening and delivered to the chemistry laboratory
the next morning.
Portable equipment was used for measuring some water quality
characteristics An the field. Temperature and specific conductance were
measured using a portable specific conductance meter. A portable pH
meter was used for determining the water pH in the field. Fecal collform
bacteria were measured each day using a portable membrane filtration
apparatus.
2.6.2 Analysis Procedures
Chemical analyses were performed using generally accepted proce-
dures. Ion chromatography was used to perform analyses for ammonia,
2-18
-------
TABLE 2-4
SUMMARY OF SAMPLE PRESERVATION AND ANALYTICAL ANALYSIS METHODS
Parameter
Sample
contai ner
Sample
preservation
Maximum
holding
time*
Analytical
analysis
method
Amonia
Nitrate/nitrite
Chiorlde
Sodium, total
Total dissolved
solids
Orthophosphate,
total
MBAS
Alkalinity
plastic
plastic
plastic
plastic
plastic
plastic
pi astic
plastic
Hardness, total plastic
(mg/1 as CaC03)
H0SO4 to pH<2
Cool to 4°C
H0SO4 to pH<2
Cool to 4°C
Cool to 4°C
HNO3 to pH<2
Cool to 4®C
Cool to 4°C
Cool to 4°C
Cool to 4°C
Cool to 4°C
HNO3 to pH<2
Cool to 4°C
28 days
23 days
28 days
6 months
2 days
2 days
1 day
28 days
6 months
Ion chromatograph
(2)
Ion chromatograph
(2)
Ion chromatograph
(2)
Atomic absorption
(Method 273.1)
(3)
Grav imetric-»dri ed
at 180°C* '
(Method 160.1)
Col orimetric^
(Method 365.2)
(3 \
Color-metric
(Method 425.1)
Colorimetric* '
(Method 310.2)
Col ori metric^
(Method 130.1)
(1)
From Federal Register Vol. 49, No. 209, 26 October 1984.
(^From manufacturer's manual.
(3)EPA (1979).
-------
nitrate/nitrite and chloride. Procedures outlined by the United States
Environmental Protection Agency (USEPA, 1979) were used to perform analy-
ses for total sodium, total dissolved solids, orthophosphate, MBAS, alka-
linity and total hardness.
2.7 Water Use Along Transects
Water use was identified along each transect. In general, water
use along a transect included all water use between the two nearest
streets that paralleled, and thus bracketed, the street along which the
transect was located.
Wastewater disposal along the transects is assumed to be equal to
water use.
2.7.1 Water Use Along Transects in Kill Devil Hills
Water used for public supply in Kill Devil Hills comes from deep
wells on Roanoke Island. There are only a few private wells in the area.
Water usage is highest in the summer months and lowest in the winter
months (Table 2-5). Quarterly water usage records from the Kill Devil
Hills water department showed that water usage along Transects Kl, K2 and
K3 during 16 June to 15 September were, respectively, 3.5, 2.1 and 10.7
times greater than that during 16 December to 15 March.
Water use varied along transects as well as between transects. The
variation in water use along a transect was most noticeable at Transect
K3. There is a considerable amount of development between well sites K3A
and K3B and very little development along the rest of the transect. The
variations in water use along Transects Kl, K2 and K3 for the period
April 1984 to March 1985 are shown in Figure 2-6. The average water use
along each transect for the period is also shown.
2.7.2 Water Use Along Transects in Atlantic Beach/Pine Knoll Shores
Water used for public supply in Atlantic Beach and Pine Knoll Shores
generally comes from deep wells on Bogue Banks, although some residents
along Transect PI in Pine Knoll Shores obtain their supply from indivi-
dual shallow welIs.
Water usage is highest in the summer months and lowest in the winter
months (Tables 2-6 and 2-7). Monthly water usage records from the
Atlantic Beach water department showed that the highest water usage along
Transects A1 and A2 during the study period occurred in August 1984. The
lowest water usage along Transect A1 occurred in February 1985 and the
lowest water usage along Transect A2 occurred in December 1984. The
ratio of high to low month water usage was 8.3 for Transect A1 and 3.3
for Transect A2. In Pine Knoll Shores the ratio of high to low quarterly
water usage from public supplies along Transects PI and P2 were 2.4 and
3.5, respectively. The high water use period occurred during the quarter
July to September 1984, and the low water use period occurred during the
quarter January to March 1985 along both transects. These records were
provided by the Carolina Water Service Company who supplies water to Pine
Knoll Shores.
2-20
-------
TABLE 2-5
SUMMARY OF WATER USAGE ALONG TRANSECTS IN KILL DEVIL HILLS^
1984 1984-1985
Transect March 16- June 16- September 16 December 16- Total
ID June 15 September 15 December 15 March 15
K1 322.8 744.0 392.4 211.2 1,670.4
K2 650.6 1,422.2 1,002.3 683.4 3,758.5
K3 268.8 1,144.4 503.8 107.2 2,024.2
^^Numbers are reported in 1,000 gallons pumped during the period.
-------
4-
3-
2-
(0 1"
0
O
•E E
<
LU
DC
<
cc
LU
OL
LU
CO
3
QC
LU
H
<
£
TRANSECT K-1
EXPLANATION
26 R
OC
n q
U OC w 1C D
32R a 7R
3C OC
TRANSECT K-2
4-
3-
2-:
1-
62 R
O C
T SOR T 2^5 I 21 R
D ocC ocB ocA
TRANSECT K-3
C WELL 3ITE LOCATION
AVERAGE WATER U8E FOR
THE PERIOD APRIL 16. 1984
TO MARCH 15, 1986
.WATER USE FOR THE
PERIOD APRIL 16, 1984
TO MARCH 16, 1986
0
l_
600 1000 1600 FEET
—I I I
R * RESIDENTIAL STRUCTURES
C s COMMERCIAL STRUCTURES
3-
2-
1-
3 R
0 C
1 R
OC
0 R
0 C
—r~
D
0 R
0 C
T"
c
0 R
0 C
Figure 2-6. Water use along transects in Kill Devil Hills,
2-22
-------
TABLE 2-6
SUMMARY OF WATER USAGE ALONG TRANSECTS IN ATLANTIC BEACH^
1984 1985
Transect
H) May June July Aug Sep Oct Nov Dec Jan Feb Mar Apr Totals
A1 254.0 596.5 673.4 692.8 359.7 212.9 190.1 257.2 172.4 83.5 141.7 260.3 3,894.5
A2 411.8 454.9 589.0 620.3 397.2 225.2 214.6 186.9 253.5 355.6 314.6 223.7 4,247.3
^Numbers are reported as 1,000 gallons pumped during the period.
-------
TABLE 2-7
SUMMARY OF WATER USAGE ALONG TRANSECTS IN PINE KNOLL SHORES^
1984 1985
Transect April 1 - July 1 - October 1 - January 1 - Total
JD June 30 September 30 December 31 March 31
PI 147.7 150.0 125.5 62.3 485.5
(Public
supply
only)
PI
(including 304.1 447.8 244.6 233.6 1,230.1
private
wells)
P2 1015.0 1912.9 551.5 543.4 4022.8
(^Numbers are reported as 1,000 gallons pumped during the period.
-------
Water use data for Transect PI are presented with and without the
individual private well water usage included in the numbers (Table 2-7).
The private wells generally withdraw water from the shallow aquifer and
thus do not present an addition of water to the shallow aquifer.
Therefore, private well water usage is not needed for a water budget ana-
lysis. However, private well water usage does impact water quality in
the shallow aquifer and was taken into account when analyzing ground-
water quality. Water usage from private wells is based on an inventory
of these along the transect and the known water use for those residents
along the transect that use public supplies.
Water use varied along transects as well as between transects. The
variation in water use along a transect was most noticeable at Transect
P2. There is a considerable amount of development between well sites P2A
and P2B and very little development along the rest of the transect. The
variations in water use along Transects A1 and A2 for the period May 1,
1984 to April 30, 1985 are shown in Figure 2-7. The variations in water
use along Transects PI and P2 for the period April 1, 1984 to March 31,
1985 are shown in Figure 2-8. The average water use along each transect
for the period is also shown.
2.7.3 Water Use Along Transects in Surf City
Water used for public supply in Surf City comes from deep wells
located on the mainland about 1.5 miles northwest of town.
Water usage is highest during the spring months and lowest in the
winter months (Table 2-8). Quarterly water usage records from the Surf
City water department showed that the highest water usage along Transects
SI and S3 occurred during the period 1 April to 30 June 1984. The lowest
water usage along Transect SI occurred during the period 1 October to 31
Decanber 1984, and the lowest water use along Transect S3 occurred during
the period 1 January to 31 March 1985. The ratio of high to low month
water usage was 1.6 for Transect SI and 3.5 for Transect S3.
Water use varied along transects as well as between transects. The
variation in water use along a transect was most noticeable at Transect
SI. Commercial development in the vicinity of site SIB accounts for a
relatively large water usage in that area of the transect as compared to
the rest of the transect. The variations in water use along Transects SI
and S3 for the period 1 April 1984 to 31 March 1985 are shown in Figure
2-9. The average water use along each transect for the period is also
shown.
2.8 Land Use Along Transects
Land use was identified in the vicinity of each transect. This
information is useful for explaining variations in water use along tran-
sects. In general, land use inventory along a transect included all land
use between the two nearest streets that paralleled, and thus bracketed,
the street on which the transect was located.
2-25
-------
CO
0)
O
c
.<
UJ
cc
<
TRANSECT A-1
EXPLANATION
C WELL 8ITE LOCATION
AVERAGE WATER U8E FOR
THE PERIOD MAY 1, 1984
TO APRIL 30. 1986
.WATER USE FOR THE
PERIOD MAY 1. 1984
TO APRIL 30. 1985
0 300 FEET
' ' ' I
R s RESIDENTIAL STRUCTURES
C « COMMERCIAL STRUCTURES
TRANSECT A-2
Figure 2-7. Water use along transects in Atlantic Beach.
2-26
-------
CO
0)
o
c
<
111
DC
<
oc
LU
0L
LU
CO
TRANSECT P-1
excluding private wells
6
5-\
4
34
TRANSECT P-1
including private wells
18 R
o c
D
irrr
0 C
4 R
OC
B
6 R
0 C
J
TRANSECT P-2
EXPLANATION
C WELL 8ITE LOCATION
AVERAGE WATER USE FOR
THE PERIOD APRIL 1, 1984
TO MARCH 31. 1885
.WATER USE FOR THE
PERIOD APRIL 1. 1984
TO MARCH 31, 1986
0
L_
800
I
1000 FEET
R = RESIDENTIAL STRUCTURES
C: COMMERCIAL 8TRUCTURE8
12-|
1 !;
4 4
3
2
1•
0 R
0 c
0 R
0 C
0 R
0 C
Figure 2-8. Water use along transects 1n P1ne Knoll Shores.
2-27
-------
TABLE 2-8
SUMMARY OF WATER USAGE ALONG TRANSECTS IN SURF CITY^
1984 1985
Transect April 1 - July 1 - October 1 - January 1 - Total
ID June 30 September 30 December 31 March 31
SI 468.1 392.7 287.1 354.2 1,502.1
S3 641.2 484.3 338.8 183.7 1,648.0
^Numbers are reported in 1,000 gallons pumped during the period.
-------
CO
©
O
c
<
111
CC
<
TRANSECT S-1
EXPLANATION
12"
10-
8
6
4
2
1 R
0 C
~r
B
10 R
1 C
C WELL SITE LOCATION
AVERAGE WATER U8E FOR
THE PERIOD APRIL 1,1984
TO MARCH 31. 1985.
.WATER USE FOR THE
PERIOD APRIL 1. 1984
TO MARCH 31, 1986.
0
L
100
200 FEET
Rs RESIDENTIAL STRUCTURES
Cr COMMERCIAL STRUCTURES
cc
LU
0.
UJ
CO
D
OC
UJ
I-
<
£
12-1
10
64
6
4H
2
TRANSECT S-3
7 R
4 C
¥
20 R
3 C
Figure 2-9. Water use along transects in Surf City.
2-29
-------
2.8.1 Land Use Along Transects in Kill Devil Hills
Land use along Transects K1 and K2 is similar. The area between
the beach and well site B along both transects is a combination of com-
mercial and residential development. The commercial development includes
restaurants, stores, motels and gas stations. This area is closest to
the ocean. The area between well sites 8 and E along both transects is
generally residential. Many of the residences along these transects are
rental properties. The general distribution of land use along transects
K1 and K2 is shown in Figure 2-6.
Development varies along Transect K3 (Figure 2-6). The area be-
tween the ocean and well site B is generally commercial. This area is
closest to the ocean. There is essentially no development between well
sites B and F. The area between well sites F and G is occupied by single
family residences who probably live in the area year-round.
There is generally little or no vegetative cover along the tran-
sects. Areas not covered by manmade structures are generally composed of
medium to coarse sands. The area between well sites F and G along
Transect K3 is an exception. Numerous trees exist in this area, although
the ground consists of medium to coarse sands.
2.8.2 Land Use Along Transects in Atlantic Beach/Pine Knoll Shores
Land use varies along Transect A1 in Atlantic Beach (Figure 2-7).
The area between well sites A and C is generally residential; many of
these dwellings are rental properties. A large drain field exists bet-
ween well sites C and D and is adjacent to well site D. This drain field
serves a-large condominium complex located at the sound.
Land use along Transect A2 in Atlantic Beach is generally residen-
tial. However, many of the residential dwellings are rental properties.
There also is some commercial development between well sites B and C.
The general distribution of land use along Transect A2 is shown in Figure
2-7.
Land use along Transect PI in Pine Knoll Shores is residential
(Figure 2-8). The area along this transect is occupied by single family
residences who generally live in the area year-round. Well site loca-
tions along Transect PI are shown in Figure 2-4.
Development varies along Transect P2 in Pine Knoll Shores (Figure
2-8). The area between well sites A and B is occupied by condominiums.
This area is closest to the ocean. There is little or no development
between well sites B and D. The area between well sites D and E is
currently being developed with multifamily residences.
There is little or no vegetative cover along Transects A1 and A2.
Areas not covered by manmade structures are generally composed of medium
to coarse sand. The drain field between well sites C and D, which has a
grass cover, is an exception.
2-30
-------
sidera^rvegetatiWe^over ^Tree^aild^*^ 1n 3reaS Wher® there 1s Con"
of these transects. * Qrass grow in the areas along both
2,8,3 Use Along Transects in Surf r^y
dcntia^al^mralrcLl^veYoSt3 tJ"!? S-h " " combinatio"of re*1:
properties. The rnmm0rH?i T , * T,1e residences are generally rental
each transect The mtsi 1 deveJopment includes a motel located within
The motel a^ong Transect S3 °"s9 &Ct ,S1 1s ,0«te<1 **" site B'
transect. The distrfbution of to well site B for that
shown in Figure 2-9. along transects SI and S3 is
coveredhby6manma^e Structu^e^Vre n?er ?]on9 the transects- Areas not
sand. uctures are generally composed of medium to coarse
2-31
-------
3-0 HYDR0GE0L0GIC CHARACTERIZATION OF THE STUDY AREAS
ground-water occurrence and movement* tl* s,hallow subsurface setting,
water levels and precipitation npt relationship between ground-
aquifer and ground-water quality were descMbed°ir|hdeta^ll0W 9round"water
the movement of ground ^ate^ r°,nmental heads are used to study
Freshwater head at any point in a™ *5le densit* (Lusczynski, 1961).
defined as the level of freshwater that ^0f var1ab1e density is
pressure at the well screen Fnvirnnm would be required to balance the
of variable density watlr Sccumnc ,T^a' head 1s def1ned as the ,evel
that would be required to balance the pressUreUrt%h?0,iithe WeH
pressure at the well screen.
3,1 -ydrQ??eo1oqy of the Ki" Hills st..wr ftrrn
3.1.1 General Hydroqeolngy
tain fresh waterd(PeakUnetea1iainiq7?^hreThac,uifers that are known to con"
generally fine to medium saJd extendia(lu1fer' consisting of
depths varying between 30 and 80 feet d°wnwa.rd ,frf 1and surfac® t0
predominantly medium-grained sand, underliS PtZ°CTi\ a^lfef' whlcJ Is
about 50 feet thick Tho in»». es the shallow aquifer and is
and is composed of interbedded clav andVnderl1eS the PrinciPal aclu1fer
in thickness between 50 and 100 feet Bph^V31^5* This a9uifer varies
to 140 feet thick separate the shadow an^°f Vn and clay that are 120
and divide the principal aquifer 'l?toT ®r fr0m the PrinciPal ac»uifer
Beds of clay, siltv clav and riaJl, ^ sections under the island.
to 80 feetf separate the princ^Ml S?„n,?,,Wh0se thtckness "aries from 30
hydrogeoloaic cross eBrtinn 5i C1P3' and lower aquifers. A generalized
the study area is shown in Figure 3_f°rtion of B°die Island that includes
3.1.2 Hydrogeoloqy of the Shallow Aquifer
the o^m^cte™molt'b^the'us^oftn sTt this. reP°rt« Thl's ^uifer ^
disposal of wastewater natf r!!n systems for the treatment and
Transects K1. K2 and K3*{see Flqure /°l 1 f the Ke,'S dH"ed "l0"9
\ ngure 3-1) formed the basis for the study.
3*1.2.1 Geologic Setting
of fin^to^TOd^um3 sancfwith \^ome Vnterbedrf harea 1s composed ™°st,J
of organic silt and peat near laM s5Sar» n ""*S and °ccurre"c-s
material Dartialiv rnn«n« Zu 1 surface. The near-surface organic
sent. Silts and clays 1nterbPd£fr ?P. areas where the material is pre-
feet below land surface Vf!?5 ^ occur '! 6-5 t0 100
sections deDictinn t-hQ naf tne base of the aquifer. Geologic cross-
are presented ?n Figure 3-2.re Sha1,ow a"u1fer in K11' Dev1' H11,s
3-1
-------
¦••• Map (ran Paali and olk»». 1172. 9 1 ? ? f 9 mil«»
a. Location map for generalized hydrogeologic cross-section.
b. Generalized hydrogeologic cross-section.
Figure 3-1. Generalized hydrogeologic cross-section for Bodle Island.
-------
TRANSECT K1
TRANSECT K2
>01
SEA LEVEL
ALBEMARLE £
SOUN£_
-100 J
CO
I
CO
TRANSECT K3
1000 FEET
Fin* Mud
wit It i«m ctey
SHt and oond
20' »0*
.SEA LEVEL
-20* -20:
-40' -40:
-eo' -«o:
.-60* -80'.
-too' - too:
: ¦' Study »Wt SMy. ctay ^
Silty cloy «nd clay
1000 FEET
OCEAN
V
FIm to oodlww
7i>**
rrrTMtMM«d*d dWy«9>Sv
mi. BH»: lw»: wiwt:
Coaru aand
Fin* to cooroo uitd
with •hollo
.20"
.SEA LEVEL
Clayoy •». «M Md
•ttty Hm M*d
EXPLANATION
Hell site showing location of well
screen setting. Multiple wells are
completed at most sites
-2- Generalized water table
I—| Shallow aquifer
FTT1 Confining beds
i
Figure 3-2. Hydrogeologic cross-sections for the shallow aquifer at Kill Devil Hills.
-------
3.1.2.2 Ground-Water Occurrence and Movement
Ground water is present in the pore spaces of the saturated deposits
that underlie Bodie Island. The intergranular pore spaces in the sands
serve as the storage space for water in the shallow aquifer and as path-
ways for water movement. The pore spaces in clayey confining beds also
serve to store water. However, these pore spaces are extremely small,
making the movement of water through those deposits difficult.
Ground-water movement in the shallow aquifer is generally away from
the central part of Bodie Island toward discharge points in the ocean and
the sound (Figures 3-3 and 3-4). These flow directions were defined from
the distribution of freshwater heads in the aquifer as measured by water
levels in the monitoring wells. There were no significant differences in
density of the ground water in the monitoring wells. Ground water flows
from areas of higher head to areas of lower head.
Some ground water from the shallow aquifer discharges downward into
the underlying confining beds. The head observed in well K2C4, completed
within the confining beds, is substantially lower than that observed in
the shallow aquifer. This indicates that there is downward flow into the
confining beds (see Figures 3-3 and 3-4).
Normal ground-water flow patterns along the transects varied only
slightly between summer and winter. Flow patterns in August 1984, which
are representative of summer conditions, are shown in Figure 3-3. Flow
patterns in February 1985, which are representative of winter conditions,
are shown in Figure 3-4.
Heavy rains and high tides resulting from hurricane Diane in
September 1984 caused reductions in ground-water flow toward the ocean
along each of the transects. These changes were most pronounced in
October (Figure 3-5). By December, however, ground-water flow was essen-
tially the same as that normally observed during the study.
The ground-water flow velocity throuyh the shallow aquifer varies
from 0.1 to 1.5 feet per day (ft/day) but typically averages 0.7 ft/day
(Table 3-1). This velocity was computed from the equation:
V - {jl (1)
where: V = velocity, in feet per day;
K = horizontal hydraulic conductivity, in feet per day;
I = hydraulic gradient, in feet per foot; and
0 = effective porosity, no dimensions.
The horizontal hydraulic conductivity of the aquifer, as determined from
aquifer testing at well K3D2, is 73 ft/day. The effective porosity of
the aquifer was computed as 0.19 by correlating precipitation measured at
Kill Devil Hills with changes in water levels observed in well K3D1
3-4
-------
TRANSECT K1
-100'
r 120'
Well site showing location of well
screen setting. Multiple wells are
completed at most sites
-Z- Generalized water table
I I Shallow aquifer
m Confining beds
Line of equal freshwater head on
—6.0-February 9, 1985. Interval one
foot. Dashed where Inferred.
»- General 1zed ground-water flow
di recti on
Area of brackish water
Figure 3-3. Ground-water flowpaths in the shallow aquifer at Kill Devil Hills on August 17. 1984.
-------
TRANSECT K1
Well site showing location of well
screen setting. Multiple wells are
completed at most sites
-2- Generalized water table
I I Shallow aquifer
.SEA LEVEL Confining beds
line of equal freshwater head on
—5-0-February 9, 1985. Interval one
foot. Dashed where inferred.
»¦ Generalized ground-water flow
direction
Area of brackish water
Figure 3-4. Ground-water flowpaths in the shallow aquifer in Kill Devil Hills on February 9, 1985,
-------
TRANSECT K1
SEA LEVEL
ALBEMARLE :
SOUN^
TRANSECT K2
o
L—
1000 FEET
ALBEMARLE
SOUND -4
-80' -eo'J
100' -iooJ
CO
TRANSECT K3
ALBEMARLE
SOUMO y ^—
0
u
1000 FEET
explanation
Well site showing location of well
II screen setting. Multiple wells are
1 completed at most sites
-2- Generalized water table
I I Shallow aquifer
HI Confining beds
Line of equal freshwater head on
—5.o~October 20, 1984. Interval one
foot. Dashed where inferred.
-Generalized ground-water flow
di rection
Area of brackish water
Figure 3-5. Ground-water flowpaths in the shallow aquifer at Kill Devil Hills on October 20, 1984.
-------
TABLE 1-1
GROUND-WATER FLOW VELOCITIES AND TRAVEL TIMES
ALONG TRANSECTS IN KILL DEVIL HILLS
Site Distance
Mean
Hydraulic
Flow
Travel time
Cumulative
Remarks
between
water-table
gradient
velocity
between sites
travel time to
sites
elevation
between
sites
(feet/day)
(days)
sound or ocean
(feet)
(MSL)
(feet/foot)
(days)
Transect K1
C
6.2
1
©
0
Sound side of
800
1.38 x
0.53
1520
transect
D
5.1
1520
1075
1.86 x
10"3
0.71
1500
E
3.1
3020
C
6.2
0
Ocean side of
625
3.20 x
io_/t
0.12
5090
transect
B
6.0
5090
1000
1.80 x
10-3
0.69
1450
A
4.2
6540
Transect K2
D
6.9
0
Sound side of
1475
3.32 x
10"3
1.28
1160
1160
transect
E
2.0
D
6.9
0
Ocean side of
1225
7.35 x
10"4
0.28
4340
4340
transect
C
6.0
950
1.05 x
10"3
0.40
2350
B
5.0
6690
925
1.40 x
10
0.54
1710
8400
A
J.7
Transect K3
D
10.4
0
Sound side of
1075
1.86 x
10"3
0.71
1500
transect
E
8.4
~
1500
875
2.51 x
10"3
0.97
900
F
6.2
2400
1100
3.82 x
10"3
1.47
750
G
2.0
3150
D
10.4
0
Ocean side of
1075
7.44 x
10-*
0.28
3760
transect
C
9.6
3760
1175
2.38 x
10"3
0.92
1280
B
6.8
5040
1675
1.85 x
10" 3
0.71
2360
A
3.7
7400
3-8
-------
fS?PmSSitoHng water SsT 6qUlpped with a continuous stage recorder
IslandMs ^fmiYar t^lhat xyst?m 9round-water flow velocity under Bodie
MQ7S? fiPtPmVntri th + *1 elsewhere on the barrier islands. Winner
on Caoe Hatteras National TrT fl(?W vel°city in the shallow aquifer
on uipe Matteras National Seashore is about nno fnnt nPr dav The
National Seashore includes the southern end of Bodie Island.
are muc^^hnrt^r It® ^roynd-^ter divide on the island to the sound
are much shorter than those to the ocean (Table 3-1 h In general, the
distance ftS to'the'sound ts lefs than' the
Vntlrd thp SLJ\c dlvlde the ocean- Also, the hydraulic gradient
fin^rt^rc 1,1 ^eneral ^^steeper than that toward the ocean. These
factors reinforce each other to reduce travel times to the sound.
The shortest residence times occur when water enters the shallow
c?tiIraUpa«r^Lc
-------
0.0-
z
0
H
0.5-
<
1-
T- 111
Qz 1
0 0
1.0-
UJ z
cc -
0- z
>-
1.5-
-J
<
Q
2.0-1
I
T
l<*
Jl
OJ
i
n
O hi
_i u.
^ r,
ffi 2
DC h
PS
< o
£ °-
08 d
I- ~ 6.0 H
X D
£3
Sg
3.0-1
4.0-
5.0-
7.0
Depth to water in well K3D1
(see Figure 2-2 for location)
3.0
4.0
5.0
6.0
7.0
, 1 1 1 1 1 1 1 1
AUG SEP OCT NOV DEC JAN FEB MAR APR MAY
1984 1985
EXPLANATION
(2.99) Total rainfall for the day when the total exceeds the scale
Dashed line represents missing water level record
Figure 3-6. Relation between ground-water levels and precipitation in the Kill Devil Hills study area.
-------
24-hour periods in August 1984 and again in February 1985. Water levels
in the other monitoring wells at these times did not appear to be
influenced by tidal fluctuations.
3.1.2.4 Net Ground-Mater Recharge
Net recharge to the shallow aquifer is the difference between water
gains and water losses at the water-table surface. Water gains occur as
infiltration from precipitation and wastewater disposal. Water losses
occur as a result of evapotranspiration. Changes in water stored in the
unsaturated zone overlying the shallow aquifer influences the net
recharge and must also be taken into account.
Net recharge to the water table for a given time period can be
expressed in equation form as:
W = Ip + Iw - AS - ET (2)
Where: W = net recharge, in inches;
*p = infiltration from precipitation, in inches;
Iw » infiltration from wastewater disposal, in inches;
AS = change in soil moisture storage; in inches; and
ET = evapotranspiration, in inches.
Equation (2) represents a water budget for water gains and losses at the
water-table surface. Monthly water budgets based on equation (2) are
presented in Table 3-2 for each of the transects.
Precipitation is the major source for recharge to the shallow
aquifer. Precipitation accounted for approximately 90, 86 and 93 percent
of the recharge along Transects Kl, K2 and K3, respectively. Wastewater
accounted for the remainder of the recharge received along these tran-
sects.
All precipitation was assumed to infiltrate into the soil in this
analysis. This assumption is reasonable as the soil is permeable ana
little or no runoff is observed during most rains. Also, the storm water
collection system in Kill Devil Hills is minimal. Runoff generally ponds
in low areas and eventually seeps into the ground or evaporates.
Monthly precipitation for the analysis was determined from daily
rainfall records collected by the town of Kill Devil Hills water depart-
ment. Data for June and part of July were supplemented with tnai
collected by the National Weather Service at Manteo, located approxima-
tely eight miles southwest of Kill Devil Hills.
Wastewater disposal for the analysis was assumed to be equal to
water use. Most water used by residents in Kill Devil Hills is treated
on-site and disposed of by infiltration of the water into the ground.
3-11
-------
TABLE 3-2
SUMMARY OF RECHARGE COMPUTATIONS FOR TRANSECTS IN KILL DEVIL HILLS*1*
Transect Parameter 1984 1985 Totals
ID
June
July
Aug
Sept
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
K1
Ip
0.88
7.35
3.39
7.01
1.07
2.49
1.38
5.00
3.85
2.60
1.09
3.27
39.38
Iw
0.10
0.26
0.26
0.17
0.12
0.12
0.12
0.06
0.06
0.04
0.07
0.17
1.55
AS
-0.80
0.80
-0.80
0.80
-0.80
0.80
0
0
0
0
-0.80
0
-0.80
ET
1.68
5.82
4.19
3.87
1.87
1.19
1.06
0.12
0.27
1.22
1.89
3.27
26.45
W
0.10
0.99
0.26
2.51
0.12
0.62
0.44
4.94
3.64
1.42
0.07
0.17
15.28
K2
K3
ID
0.88
7.35
3.39
7.01
1.07
2.49
1.38
5.00
3.85
2.60
1.09
3.27
39.38
0.12
0.31
0.31
0.20
0.19
0.19
0.19
0.13
0.13
0.05
0.10
0.24
2.16
aS
-0.80
0.80
-0.80
0.80
-0.80
0.80
0
0
0
0
-0.80
0
-0.80
ET
1.68
5.82
4.19
3.87
1.87
1.19
1.06
0.12
0.27
1.22
1.89
3.27
26.45
W
0.12
1.04
0.31
2.54
0.19
0.69
0.51
5.01
3.71
1.43
0.10
0.24
15.89
Ip
0.88
7.35
3.39
7.01
1.07
2.49
1.38
5.00
3.85
2.60
1.09
3.27
39.38
Iw
0.04
0.20
0.20
0.13
0.08
0.08
0.08
0.02
0.02
0.03
0.06
0.14
1.08
AS
-0.80
0.80
-0.80
0.80
-0.80
0.80
0
0
0
0
-0.80
0
-0.80
ET
1.68
5.82
4.19
3.87
1.87
1.19
1.06
0.12
0.27
1.22
1.89
3.27
26.45
W
0.04
0.93
0.20
2.47
0.08
0.58
0.40
4.90
3.60
1.41
0.06
0.14
14.81
(1)
All values are reported in inches.
-------
Monthly wastewater disposal along each transect was estimated from
the quarterly water use records for residents along the transects. The
ratio of monthly to quarterly water use, needed to distribute water use
on a monthly basis, was assumed to be the same as that observed at
Atlantic Beach.
Monthly soil moisture changes and monthly evapotranspiration used in
the analysis were computed using methods outlined by the EPA (Fenn et
al., 1975). These methods are described in Appendix G.
3.1.2.5 Mater Quality
Ground-water samples were taken periodically for the analysis of
selected parameters (Table 3-3). Water samples were collected in July
1984, October 1984, January 1985 and April 1985 along Transect K2, the
designated high population density transect, in July 1984 and January
1985 along Transect Kl, the designated medium population density tran-
sect, and in January 1985 along the designated low population density
transect, Transect K3.
Water samples were collected with two objectives in mind. One
objective was to define the relationship between saltwater and freshwater
in the shallow aquifer. The second objective was to define the current
impact of wastewater disposal on the quality of water in the shallow
aquifer.
3.1.2.5.1 Relationship Between Freshwater and Saltwater
Measured chemical properties of the ground water used to aid in
defining saltwater intrusion into the shallow aquifer included sodium
concentration, chloride concentration, total dissolved solids con-
centration and specific conductance. Sodium and chloride are the major
constituents in saltwater. Total dissolved solids measures all solids in
solution in the water, including sodium and chloride. Specific conduc-
tance measures the ability of water to conduct an electrical current and
generally increases with an increase in total dissolved solids content in
the water.
Elevated total dissolved solids concentrations had a strong correla-
tion with elevated sodium and chloride concentrations in water from the
shallow aquifer and is a good indicator of saltwater intrusion into the
aquifer. The total dissolved solids content in the water was used to
determine the presence of saltwater and freshwater in the shallow
aquifer.
Elevated specific conductances also correlated well with increased
sodium and chloride concentrations in water from the aquifer.
Water has been classified based on the total dissolved solids con-
tent in the water (Fetter, 1980). Water with a total dissolved solids
content less than 1,000 milligrams per liter (mg/1) is considered to be
freshwater. Water with a total dissolved solids content between 1,000
and 10,000 mg/1 is considered to be brackish, and water with a total
dissolved solids content greater than 10,000 mg/1 is considered to be
3-13
-------
TABLE 3-3
summary OF GROUND-WATER QUALITY ANALYSES FOR KILL
Total Ammo-
dis- nia
solved
-------
Kill Devil Hills (cont'd)
Transect K2
K2A1
K2A2
K2A3
K281
K2B2
K2B3
K2C1
K2C2
K2C3
K 2C4
113ui84
210ct84
173an85
09Apr85
1l3ul84
210ct84
173an85
09Apr85
113ul84
210ct 84
173an85
09Apr85
11Jtil84
210ct84
173anB5
09Apr85
113ul84
210ct84
t73an85
09Apr85
113ul84
210ct94
173aii85
09Apr85
123ul84
210ct84
173an85
09Apr85
123ul84
210ct84
173an85
09Apr85
123ul84
210ct84
173an85
09Apr85
123ul84
210ct84
173an85
09Apr85
40
47
63
152
619
552
84
346
87
78
74
80
17
11
12
12
21
22
23
35
121
140
175
59
11
9
14
13
16
16
13
15
64
43
37
39
87
71
52
68
46
680*
92
250
1230
913
2317
3087
126
94
107
107
21
15
17
22
29
28
29
31
220
184
192
169
25
20
14
19
20
19
19
18
61
35
45
30
78
64
62
60
235
576
338
790
2872
1134
5938
6768
377
494
438
322
162
186
178
152
241
300
264
228
587
568
574
519
172
182
168
114
354
362
234
287
390
370
358
300
404
412
362
356
<0.01
0.27
<0.01
1.13
<0.01
0.41
1.11
0.14
0.06
0.13
0.08
<0.01
<0.01
0.02
0.02
0.14
0.07
0.10
0.47
0.46
0.49
0.61
0.52
0.85
0.49
0.80
0.27
0.42
0.33
0.55
0.39
0.55
0.17
0.42
0.09
0.15
0.14
0.22
0.54
<0.01
Nitrate
plus
nitrite
(*g/i
as N)
0.36
0.60
<0.05
3.06
0.43
0.23
0.65
1.20
<0.05
<0.05
<0.05
0.96
0.47
0.52
0.50
0.16
<0.05
<0.05
<0.05
0.67
<0.05
<0.05
<0.05
0.17
<0.05
<0.05
<0.05
0.06
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
0.80
Hardness
(ag/1 as
CaCOv)
92
104
124
125
m
148
140
131
88
105
107
104
64
61
73
80
109
121
135
154
171
202
204
201
24
23
32
46
203
236
152
225
198
255
259
213
183
220
223
210
86
0.21
508*
0.13
122
0.53
263
0.09
648
0.12
580
0.10
1224
<0.02
1361
0.07
70
0.15
82
0.08
90
0.02
94
0.04
70
0.26
74
0.08
84
<0.02
102
0.05
130
0.30
130
0.21
122
0.03
143
0.07
170
0.10
178
0.21
164
<0.02
162
0.10
32
0.27
30
0.12
250
<0.02
41
0.07
236
0.25
210
<0.02
176
<0.02
223
0.08
174
0.11
195
<0.02
182
<0.02
175
0.05
116
0.06
137
0.07
140
0.06
137
0.09
Ortho-
phosphate
(¦a/1 as P)
Teape r-
ature
*C
Specific
conductance
(pihos/cw)
PH
(s.u.)
ecdi
coli form
(colonies
per 100/
wl)
0.53
0.16
0.18
0.19
0.19
0.02
0.04
0.03
0.50
0.45
0.46
0.41
1.51
0.04
0.07
0.07
0.39
0.38
0.37
0.37
0.29
0.26
0.26
0.30
0.67
0.73
0.99
0.59
0.19
0.34
0.32
0.37
0.27
0.37
0.46
0.63
0.13
0.35
0.31
0.34
22
19
16
17
21
16
25
17
22
16
18
16
24
19
15
16
22
16
18
18
23
16
19
18
25
19
15
18
24
16
8
19
23
16
18
18
22
16
18
18
321
3200
455
1040
4110
3200
7000
9100
580
480
600
590
240
210
187
232
350
310
305
358
1050
950
950
900
211
125
110
151
459
430
440
422
230
480
490
435
600
480
495
580
8.12
7.10
7.24
7.95
7.66
7.45
7.38
7.56
7.77
7.70
7.54
7.65
6.73
6.70
6.73
6.60
7.63
7.74
7.50
7.77
7.44
7.56
7.56
7.62
5.73
6.03
5.92
5.42
6.39
6.96
6.75
7.00
6.82
7.16
6.71
6.55
6.93
7.46
7.22
7.52
-------
du
t'c
29
24
26
31
13
14
14
18
2*
22
14
26
11
15
13
16
11
11
9
16
92
53
57
80
10
12
44
30
SUMMARY
TABLE 3- i
_ (continued)
OF GROUND-WATER QUALITY ANALYSES
FOR KILL
DEVIL HILLS
Chlo-
ride
Total
dis- nia
solved (ng/1
solids as N)
Witrate
plus
nitrite
(«g/l
as N)
Alkalin-
ity (mg/1
_as CaCOj)
Hardness
(mg/1 as
CaCOu)
Fecal
coiiform
(colonies
per 100/
ml)
22
14
30
27
31
27
27
26
33
37
36
37
187*
27
23
22
12
13
12
12
198
34
158
164
156
162
182
178
204
266
220
215
240
258
238
240
175
204
168
157
183
196
108
161
532
440
390
520
0.20
0.02
0.11
1.90
1.12
1.64
0.34
0.28
0.32
0.60
0.31
0.99
0.71
0.88
0.90
0.34
0.18
0.28
0.04
0.41
0.20
0.22
0.23
0.42
<0.05
0.83
1.52
1.70
<0.05
0.05
0.78
0.08
<0.05
<0.05
0.26
0.91
0.42
0.05
<0.05
0.23
<0.05
<0.05
0.07
0.30
<0.05
<0.05
<0.05
0.09
33
41
58
61
106
127
114
122
109
148
137
147
32
18
35
85
110
126
107
103
114
131
133
127
36
0.07
<0.01
22
0.50
0.16
52
0.02
0.14
56
0.07
<0.01
140
<0.02
0.43
134
0.16
0.50
124
0.02
0.31
139
<0.02
0.61
124
<0.02
0.08
145
0.24
0.28
144
0.06
0.21
147
<0.02
0.31
38
0.13
0.53
42
0.10
0.54
100
<0.02
0.86
56
<0.02
0.50
124
0.05
0.43
116
0.23
0.40
92
<0.02
0.50
94
<0.02
0.43
130
0.12
0.29
165
<0.02
0.30
170
<0.02
0.30
192
<0.02
0.26
23
19
15
17
22
15
19
18
22
15
18
18
23
18
13
17
22
15
18
17
22
15
18
17
326
185
245
289
311
310
310
330
285
340
350
369
188
185
150
198
275
230
200
210
850
700
750
760
5.90
6.53
6.67
6.32
6.01
6.99
6.99
6.95
6.28
7.39
7.00
7.44
6.35
6.22
5.98
6.05
8.02
7.88
6.91
8.14
7.42
7.47
7.42
7.49
<1
8
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
-------
FABLE 3-3
(continued)
SUMMARY OF GROUND-WATER QUALITY ANALYSES FOR KILL DEVIL HILLS
Nitrate
Fecal
Total
Ammo-
plus
coliform
dis-
nia
nitrite
Alkalin-
Hardness
Ortho-
Temper-
Specific
(colonies
Well
Sampling
Chlo-
solved
(mg/1
(mg/1
ity (mg/1
(mg/1 as
MBAS
phosphate
ature
conductance
pH
per 100/
ID
date
Sodium
ride
solids
as N)
as N)
as CaCOi)
CaCO,)
(mq/1)
(mq/1 as P)
°C
(unhos/cm)
(s.u.)
ml)
Kill
Devil Hills
(cont'd)
Transect K3
K381
163an85
9
13
56
4.38
<0.05
18
80
0.03
0.14
14
75
5.58
<1
K3C1
163an85
11
13
150
6.88
<0.05
31
44
<0.02
0.54
14
70
6.51
<1
K3D1
163an85
11
14
28
1.72
<0.05
5
28
<0.02
0.54
18
no
7.88
<1
K3D2
163an85
21
50
188
2.87
<0.05
38
56
<0.02
0.45
14
260
7.17
<1
K3D3B
163a n85
62
148
366
1.28
0.11
148
130
<0.02
0.47
18
750
8.24
<1
K3E1
163an85
8
7
18
1.26
<0.05
33
52
<0.02
1.02
15
65
8.34
<1
K3F1
163an85
60
11
102
1.13
<0.05
7
20
<0.02
0.09
14
42
7.63
<1
K3G1
163an85
21
27
296
2.62
<0.05
174
158
<0.02
1.14
14
300
6.08
<1
K3G2
163an85
7
10
230
2.02
<0.05
93
19';
<0.02
1.04
17
160
6.84
<1
K3G3
163an85
4
255
670
2.57
<0.05
109
160
<0.02
0.87
18
1000
7.41
<1
(,,A11 analyses are in milligrams per liter (mg/1) unless otherwise noted.
~Results verified.
-------
saline. Saltwater from the ocean typically has a total dissolved solids
content of about 35,000 mg/1.
Freshwater generally exists within the shallow aquifer at Kill Devil
Hills. The total dissolved solids content of the water was less than
1,000 mg/1 at all well sites except K1A, K1C and K2A (Table 3-3).
Variations in the total dissolved solids content of water in the
shallow aquifer are apparent (Figure 3-7). Water with a total dissolved
solids content of about 200 mg/1 occurs along the water-table surface at
Transect K2. The total dissolved solids content in the water increases
with depth and is generally 400 to 600 mg/1 at the aquifer base.
Elevated levels of total dissolved solids occur near the ocean where
freshwater and saltwater begin to come into contact.
3.1.2.5.2 Effects of Wastewater Disposal
Measured chemical properties of the ground water used to aid in
defining the effects of wastewater disposal to the shallow aquifer
included nitrate plus nitrite concentration (nitrate/nitrite), ammonia
concentration, orthophosphate concentration, methylene blue active
substances (MBAS) concentration and fecal coll form concentration.
Nitrate, nitrite, ammonia and orthophosphate are common nutrients present
in wastewater. MBAS are substances used 1n detergents and that do not
occur naturally in the environment. Fecal collform are a group of bac-
teria which come from the intestines of mammals and may be found In
wastewater and sometimes storm water runoff.
Nitrate/nitrite and ammonia, reported in mg/1 as nitrogen (N), were
detected in ground water along all three transects (Table 3-3).
Nitrate/nitrite levels are generally higher at the water table surface
while ammonia levels are generally higher below the water table along
Transects K1 and K2. Relatively high levels of ammonia and low levels of
nitrate/nitrite were measured at most monitoring wells along Transect K3.
Variations in nitrate/nitrite and ammonia concentrations along Transect
K2 are shown in Figures 3-8 and 3-9, respectively.
Nitrate, nitrite and ammonia are contaminants which are commonly
found in ground water. The presence of these constituents in the shallow
ground water could, therefore, be indicative of the impact of wastewater
disposal. The highest observed levels of nitrate/n1trite and ammonia
were 3.06 mg/1 and 6.88 mg/1, respectively. The drinking water standard
for nitrates is 10 mg/1 as nitrogen. There are no drinking water stan-
dards for ammonia.
Orthophosphates, reported in mg/1 as phosphorus (P), generally
decreased 1n concentration with depth, but exceptions to this were not
uncommon (Table 3-3). Variations 1n the orthophosphate concentration
along Transect K2 are shown 1n Figure 3-10.
The presence of phosphorus compounds 1n the ground water 1s probably
due to wastewater disposal. The usual sources for phosphorus are organic
waste products and phosphate detergent residues. The highest observed
level of orthophosphate was 1.51 mg/1. There are no drinking water stan-
dards for orthophosphates.
3-18
-------
20'
SEA LEVEL.
-20:
-401
-60:
-80'
-1001
-120:
ALBEMARLE
SOUND -X
.20'
•SEA LEVEL
Q
E
o
o
O
<
CC
I-
z
111
o
z
o
o
Site E Well Site D
r20'
.-40*
r«0'
.-eo'
r 100'
r 120
20-
E1
18-
10-
8-
20.
E2
16-
10'
6-
0.
20"
E3
18-
10-
8-
llll
JA80NDJFMAM
aoH
15
10-
6-
0
D1
^ 111 ¦ 11111 >-
80-
18-
10'
6
0.
D2
il 1 ill ilr-
20-
1#
10-
8
0.
D3
1 ¦ 111111111
JASONDJFMAM
Well Site C
'¦Hiilir
•IASONDJPMAM
Well Site B
B1
Well Site A
10-
1S-
10
a
*0
16-
10
6-
0
#0-
IS-
10
6-
0.
B2
B3
llll
JASONOJFMAM
10-
18
10-
8-
0,
A1
ui
|t«H
IS
10-
8-
a
A2
i
20
18
lO-
ft
A3
JASONDJPMAM
EXPLANATION
X Generalized water table
Well site showing location
"I of sampling Intervals
TDS concentration. Number 1n
All parenthesis represents observed
Ml concentration when the vertical
scale Is exceeded
Figure 3-7. Variation 1n total dissolved solids concentration along Transect K2.
3-19
-------
CO
<
0.
SEA LEVEL.
-20
-40:
-601
-80'.
-1001
-12011
3 Mi
O £
2 ^
oc
Shallow
E2
aquifer
D2
ici
IIC2
61
B2
ATLANTIC
OCEAN
V
A1
A2
0
L.
1000 FEET
I
WaM Site E Well Site D Well Site C Well Site 3
0)
(0
o>
E
Z
o
H
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z
LU
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z
o
o
E1
too-
.76.
.60-
¦
.26-
I |
I T ?, !i
E2
too-
.76-
.60-
.25'
1
* * i f i rJ
i * i i i l » ' ¦ 11
E3
IPO-
.76-
.60-
.26-
* *
JASONOJFMAM
D1
too-
OJ
10
O
N
.76-
w
r"
.60-
.26.
*
D2
too.
.7#-
•60-
.26-
* T
«
D3
too-
.76-
AO-
.28-
# * 1
1 1
JA80NDJFMAM
100-
C1
.75-
.50-
.25-
• # * ¦
C2
100-
.75*
.60-
.25-
* * * ~
100-
C3
.76-
.50-
.25-
A
too-
C4
.76-
.60-
.26-
* » *
JA60NDJFMAM
too
.76
.60
.25
0'
B2
moo
.76-
.60
25-
0
# #
TTT
B3
• I
TTTTTTr
JA80N0JFMAM
.20'
SEA LE\f I
.-20'
-40'
-60'
-100'
-120"
Well Site A
lOO-
JO-
.60-
.26-
0-
A2
u
too
.78-
.60-
•2#-
0
A3
¦ 11 • ¦ 11«¦.
JASONDJFMAM
EXPLANATION
Generalized water table
Well site showing location
of sampling intervals
Ml Nitrate/Nitrite concentration.
U)J Number in parenthesis represents
,j| minimum probable concentration
« when the vertical scale 1s
exceeded
^ N1trate/N1trite not detected
1n analysis
Figure 3-8. Variation in nitrate plus nitrite concentration along Transect K2.
3-20
-------
sea level.
-20
-40:
-co:
-so:
-1001
0
-120U L.
ALBEMARLE
SOUNO -J
E 2
01 5
Shallow
102
03
aquifer
DC2
I B2
A2
.SEA LEVEL
-40'
1000 FEET
_J
r6 0'
.-100'
.-120*
Well Sitft f Well Site D Well Site C Well Site B Well Site A
2
too.
to
.76.
(0
¦SO-
o>
.28.
6
oi
c
Z
too.
o
.7#.
<
.60.
GC
.26.
h
2
uj
O
z
IflO-
o
.76"
o
¦60-
.26.
0.
E1
E2
^ 11 i 1111 f
E3
JA60NDJFMAM
too.
.76-
.60-
.26-
0-
D2
U
.76
.60-
.26-
0
D3
IU
JAIONOJPMAM
too
.75*
40
.26.
0
C1
I 1 1 1.
too*
.76-
.60
.26 <
0
C2
iiu
too-
.76.
.80.
.26
0
C3
I.
too
.76.
40.
.26.
0
C4
ll l 11
JASONDJFMAM
too-
.76
.60
.26-
0
B1
too
.76
j60
.26
0
B2
I,
too-
.76-
.60<
26
0.
B3
01
TT
JASONDJFMAM
tooH
.76
Mb
M
O
A1
7('
BO
M
O
> l i i
A2
too
78'
.60.
.26
0
A3
JA8ON0JFMAM
EXPLANATION
S Generalized water table
-J Well site showing location
"I of sampling intervals
Ammonia concentration. Number 1n
2j parenthesis represents observed
| concentration when the vertical
w scale Is exceeded
* Ammonia not detected 1n analysis
Figure 3-9. Variation in ammonia concentration along Transect K2.
3-21
-------
ATLANTIC
SEA LEVEL.
-20!
-601
-100!
-120 J
ALBEMARLE
SOUND
20'
.SEA LEVEL
0
u
1000 FEET
Well Site E Wall Site D Well Site C Well Site B
too
.76
.60
.26
0
too
.76
j60
.26
0
B1
¦ T . . I. . I ¦
B2
LLLL
100
.78-
.BO-
26
0
B3
1111
JASONOJFMAM
.-20'
.-40'
.-80'
r 120'
Well Site A
EXPLANATION
J Generalized water table
-j Well site showing location
"I of sampling Intervals
I Orthophosphate concentration.
t Orthophosphate not detected 1n
analysis
Figure 3-10. Variation in orthophosphate concentration along Transect K2.
3-22
-------
MBAS were detected at all wells along Transect K2 during the course
of the study (Figure 3-11). This observation indicates that wastewater
disposal has penetrated the entire thickness of the shallow aquifer and
has also penetrated the confining beds underlying the aquifer in the
vicinity of the transect. Higher levels of MBAS were generally detected
at the water-table surface whereas lower levels were generally detected
with depth. The highest observed level of MBAS was 0.53 mg/1. This
value was noted in water from well K2A1 in January 1985 and is the only
sample in which MBAS exceeded the recommended secondary drinking water
standard of 0.50 mg/1.
Very minor concentrations of MBAS were detected in water along
Transect K1 and essentially no MBAS were present in water along Transect
K3 (Table 3-3).
Fecal coliform were found in only two of the 100 ground-water
samples collected in Kill Devil Hills. Fecal coliform levels of eight
colonies per 100 milliliters of sample (col/100 ml) were detected at well
K2D1 in October 1984. The fecal coliform count in water from well K2E2
was 63 col/100 ml in July 1984 (Table 3-3). Fecal coliform were not
detected in water samples taken from these wells at other times of the
year. Also, fecal coliform were never detected in water samples from the
other monitoring wells. Fecal coliform are an indicator parameter useful
for detecting the presence of domestic wastewater in the ground water.
Alkalinity and hardness of the ground water were measured as overall
indicators for water quality (Table 3-3). Alkalinity is a measure of the
carbonate and bicarbonate ions in the water, with maximum levels of
approximately 400 mg/1 as calcium carbonate (CaC03) considered to repre-
sent no health problem. Hardness is a measure of the amount of calcium,
magnesium and iron in the water.
Alkalinity generally increased with depth in the shallow aquifer.
The alkalinity of the water was typically less than 100 mg/1 as CaC03 at
the water-table surface and between 100 and 250 mg/1 as CaC03 below the
water table surface. The alkalinity of the water is in the range of that
generally found in ground waters.
The hardness of the water also increased with depth in the aquifer
(Table 3-3). Hardness was generally less than 100 mg/1 at the water
table and between 100 and 300 mg/1 elsewhere in the aquifer. Water is
generally considered to be hard water when the hardness exceeds 150 mg/1.
The water hardness at well sites K1A and K2A near the ocean appears
to be anomalous. These anomalies are probably associated with increases
in calcium and magnesium associated with saltwater.
3-23
-------
SEA LEVEL.
-eo:
-80'.
-1001
ALBEMARLE
SOUNO -J
r20'
.SEA LEVEL
1000 FEET
.-40'
.-60'
.-60'
r 100*
-120'
Well Site E Well Site D
.eo-.
.60.
.40.
-30-
.20.
O)
.10-
E
oi
c
.eo-
Z
.60'
o
.40
V—
.30.
<
.20-
cc
.10-
»-
0-
z
UJ
o
.eo-
z
•SO'
o
.40'
o
.30-
.20-
.10'
O-l
E1
U
E2
J
E3
jasonoj fmam
•°1
D1
.so-
.40-
.30-
M-
.10'
¦
¦ 1
1
.00-
D2
,60-
,40-
.30-
.20-
.10-
.
.eo-
D3
.BO-
.40-
,30-
.20'
.10'
.
i .
JA30NDJFMAM
Well Site C
Well Site B Well Site A
11 r 11
JASONDJPMAM
EXPLANATION
Generalized water table
Well site showing location
of sampling Intervals
I MBAS concentration
# MBAS not detected In analysis
Figure 3-11. Variation in MBAS concentration along Transect K2.
3-24
-------
3-1-3 Summary of Hydrogeoloqic SetM^ for the Kill npyjl Hills Study
tudeVand' to Wentlfy'the'LJstl'iw 'hqSua9mv°of h
-------
a. Location map for generalized hydrogeologic cross-section.
SEA LEVEL—|
-50'-
-100-
-150-
' -200-
-250-
I
§
L
Sand and sheSs
Sand and sheds
\
-SEA LEVEL
-
SO'
&and and .lit
Sand and silt
—100'
150'
Limestone aquifer
200'
250"
Vertical exaggeration X 40
2000 4000 6000 FEET
—I 1 I
b. Generalized hydrogeologic cross-section.
Figure 3-12. Generalized hydrogeologic cross-section for Bogue Banks.
-------
3.2.2 Hydroqeoloq.y of the Shallow Aquifer
study? ' ' P1 and P2 (see 9ure 3-12) formed the b»sis for the
3.2.2.1 Geologic Setting
siity^sands^ocrurr?nnffn TSiStS °f fine t0 TOd1um sands with Tenses of
occur between 25 and , lay,s» and sllty fine sands which
aauifer raniL! 65 fee* below land surface form the base of the
aquifer*in th* a?i ^rOSDS"S!c/ti.ons showir»9 the nature of the shallow
in Figures 3-13 and'ln. h/Pl"e Kn011 Sh°reS StUdy area are Presented
and Pilne knoin thf s.hallow ^ifer varies between Atlantic Beach
posed of finJ cam i ar ..Beach, the aquifer is generally com-
the anuifll ® Vl es of Sllt* fine sand- In pine Kno11 Shores,
ces of oraani1^ ^Posed of fine to medium sands with occurren-
materiai nalJia?!! and Peat near land surface. The near-surface organic
sen^ partially confines the water in areas where the material 1s pre-
3*2.2.2 Ground-Water Occurrence and Movement
saturaS"^ wat?* HuT6861? in the pore spaces of the unconsolidated
soacpc d®P°sits that underlie Bogue Banks. The intergranuU# pore
aauifpr Tni « SanM? servf as the storage space for water 1n the shallow
and 5 ^ Path*fa^s water movement. The pore spaces in the silt
soar® confining beds also serve to store water. However, these pore
sits difficultreme^ small, making movement of water through those depo-
uncon«n??Ud+^s..a^so Prese"t in the limestone that underlies the
ODenin^l ^ fu ^P05^5, Interconnected joints, fractures and solution
Penings in the limestone store and transmit water freely.
Boa(ieGHan!iId"Vlater .mo.ye,n®nt is generally away frcan the central part of
3-is u -?war? discharge points in the ocean and the sound (Figures
butinn Jhefe flow directions were defined from the distri-
levoic ? ^eshwater heads In the aquifer, generally as measured by water
ri#>n
-------
TRANSECT A1
20'
O
UJ
o
>
O
o
<
2
SEA LEVEL.
-201
-40'.
-60'.
-80li
-100:
-120*.
BOQUE
SOUND
Ui
Ui
>
<
o
UJ
>
<
z
m
m
UJ
<
z
<
Ui
ui
»-
<0
H
O
»-
o
d
V)
a.
(0
o
Ui
-J
1
_j
1
5
_j
1
UJ
1
Ui
1
*
5
ATLANTIC
v OCEAN
Fine to medium
•and and shells
500 FEET
3EA LEVEL.
-201
-eo:
-eo:
-100*.
-1201
-140'.
- 160'J
TRANSECT A2
201
Jntarbadded ailly
.day. silt .end atfty:
: fin*
- Finq medium
: sand: and: sftslts
500 FEET
—l
Clay and Bill
Fins tsnd
and «h«lli
fin* l«
send and shslls:
Silly fins sand
f
EXPLANATION Um•,"
Well site showing location of well
screen setting. Multiple wells are
completed at most sites
-2- Generalized water table
~ Shallow aquifer
m Confining beds
20'
SEA LEVEL
.-20'
-40'
.-60'
--80'
_-100'
Ir 120'
_ 20'
.SEA LEVEL
.-60'
.-80'
100'
.-120'
.-160'
Figure 3-13. Hydrogeologic cross-sections for the shallow aquifer at Atlantic Beach.
3-28
-------
TRANSECT PI
-to:
-40:
-•O*.
.«£* LEVEL
EXPLANATION
T Hell site showing location of well
I screen setting. Multiple wells are
1 coopleted at Most sites
Generalized water table
I I Shallow aquifer
m Confining beds
TRANSECT P2
Figure 3-14. Hydrogeologlc cross-sections for tbe shallow aquifer at Pine Knoll Shores.
-------
TRANSECT A1
20
SEA LEVEL
-201
-40'.
-60
-ao:
-100t
-120'.
BOGUE
SOUND
ATLANTIC
V OCEAN
500 FEET
_i
20'
.SEA LEVEL
-20'
-40'
^-60'
.-80'
.-100'
L- 1 20'
TRANSECT A2
201
SEA LEVEL.
-20i
-601
-100'.
-120:
-140'.
BOGUE
SOUND
0
-160'J L.
600 FEET
r20'
SEA LEVEL
,-20'
.-80'
-100'
.-120'
f
explanation
Well site showing location of well
screen setting. Multiple wells are
completed at most sites
Generalized water table
Generalized ground-water flow
direction
I | Shallow aquifer »
m Confining beds .i
Line of equal freshwater head n \\V Area of brackish water
—s.o-on August 19, 1984. Interval
variable
Figure 3-15. Ground-water flowpaths in the shallow aquifer at
Atlantic Beach on August 19, 1984.
3-30
-------
TRANSECT P1
ATLANTIC
rr OCEAN
-401
,20'
.SEA LEVEL
r 20'
.-40'
-60'
I
EXPLANATION
Well site showing location of well
screen setting. Multiple wells are
completed at most sites
Generalized water table
I | Shallow aquifer
FTT1 Confining beds
Line of equal freshwater head
—«-°-on August 19, 1984. Interval
variable
»• Generalized ground-water flow
direction
Area of brackish water
Figure 3-16. Ground-water flowpaths in the shallow aquifer at Pine Knoll Shores on August 19, 1984.
-------
TRANSECT A1
201
SEA LEVEL.
-201,
-40
-60
a
UJ
i-
55
a
>
o
o
<
-so:
-100:
-120
UJ
>
<
z
GO
UJ
CD
UJ
£
O
1-
<0
-------
TRANSECT P1
20!
-20:
-40;
-SO'.
600 FEET
_I
ATLANTIC
c-7 OCEAN
.20'
SEA LEVEL
.-20'
-40'
rt0'
EXPLANATION
Wtell site showing location of well
screen setting. Multiple wells are
completed at most sites
-Z- Generalized water table
f
I | Shallow aquifer
fTH Confining beds
Line of equal freshwater head
—b.o—on February 11, 1985. Interval
variable.
~¦Generalized ground-water flow
direction
Area of brackish water
CO
I
-------
Movement of brackish water parallel to freshwater was not detected
at the other transects in the study area in August 1984. However,
brackish water was found in the confining beds at Transect A1 and at the
base of the shallow aquifer near Bogue Sound at Transect P2 (Figures 3-15
and 3-16).
Normal ground-water flow patterns along Transects Al, PI and P2
varied only slightly between summer and winter. Flow patterns 1n August
1984, which are representative of summer conditions, are shown in Figures
3-15 and 3-16. Flow patterns in February 1985, which are representative
of winter conditions, are shown in Figures 3-17 and 3-18.
The heavy rains and high tides resulting from hurricane Diane in
September 1984 appeared to have significantly altered ground-water flow
paths along Transect A2. Movement of brackish water parallel to fresh-
water was not detected along this transect between September 1984 and May
1985. The typical flow pattern along Transect A2 from the late fall of
1984 to M^y 1985 is shown in Figure 3-17.
The September rains and high tides caused some changes 1n ground-
water flow along Transects Al, PI and P2. These changes generally
included a reduction in ground-water flow toward the ocean. By December,
however, ground-water flow was essentially the same as that normally
observed during the study.
The ground-water flow velocity through the shallow aquifer varies
from less than 0.1 ft/day along Transect P2 to about 1.6 ft/day along
Transect Al (Table 3-4). These velocities were computed using equation
(1). The hydraulic conductivity of the aquifer used in the computations
is 63 ft/day. This value was determined from an aquifer pumping test
performed at well P2C2. The effective porosity of the aquifer was com-
puted as 0.20 by correlating precipitation measured at Atlantic Beach
with changes 1n water levels observed in well P2C1 (Appendix F). Well
P2C1 was equipped with a continuous stage recorder for monitoring water
levels.
The shallow aquifer system ground-water flow velocities found
elsewhere on the barrier islands fall between those found in the Atlantic
Beach/Pine Knoll Shores area. The average flow velocity in the shallow
aquifer on Bodie Island in the Kill Devils Hills study area is about 0.7
feet per day (see Section 3.1.2.2). The average flow velocity in the
shallow aquifer at the Cape Hatteras National Seashore, located northeast
of Bogue Banks and south of Bodie Island, is about one foot per day
(Wirmer, 1975).
The flowpath traveled by a water particle and the flow velocity of
the particle determines the time that the particle will remain in the
aquifer. The travel time from the ground-water divide on the Island to
the ocean along flowpaths at Transect Al 1s a little more than one year.
Water traveling from the ground-water divide at Transect P2 may remain In
the aquifer for several decades before discharging to the sound. Flow
times along transects from the ground-water divide to the ocean and sound
are presented in Table 3-4.
3-34
-------
TABLE 3-4
GROUND-WATER FLO* VELOCITIES AMD TRAVEL TINES
ALONG TRANSECTS IN ATLANTIC BEACH AND PINE KNOLL SHORES
Site
Distance
between
sites
(feet)
Mean
water-table
elevation
t"SL)
Hydraulic
gradient
between sites
(feet/foot)
Flow
velocity
(feet/day)
Travel tine
between sites
(days)
Cumulative
travel time to
sound or ocean
(days)
Remarks
Transect A1
B
375
C
300
8.00 x 10_<>
5.00 * 10"3
0.25
1490
190
0
1490
Sound side of
transect
D
2.4
1680
B
A
4.2
3.2
2.67 x 10"3
0.84
440
0
440
Ocean side of
transect
Transect A?
B
610
C
4.2
2.6
2.54 x 10" 3
0.80
790
0
790
Sound side of
transect
B
A 565
4.2
3.2
1.77 x 10-3
0.56
1010
0
1010
Ocean side of
transect
Tranm«<»»
C
D
E 600
5.4
' «o
1.09 x 10"3
2.00 x 10"3
0.34
0.63
1610
950
0
1610
2560
Sound side of
transect
C
B 588
600
n
5.4
5.1
4.3
5.10 x lO"4*
1.33 x 10"3
0.16
0.42
3660
1430
0
3660
5090
Ocean side of
transect
Transect P>
B
c 1610
D
960
4.0
3.5
2.6
2.5
3.11 x UT4
1.75 x 10"3
1.04 x 10-4
0.10
0.55
0.03
16500
940
29300
0
16500
16990
46290
Sound side of
transect
8
A
4.0
3.2
1.37 x 10"3
0.43
1360
0
1360
Ocean side of
transect
3-35
-------
The shortest residence times in the shallow aquifer occur at the
water table surface near the ocean and sound. Flowpaths are shortest and
flow velocities are greatest in these areas. The travel time to the
ocean along Transects A1 and PI for water particles entering the shallow
aquifer at well sites A1A or P1A is typically one to two months. The
travel time from well site AID to the sound along the water table at
Transect A1 is about two months, and the travel time from well site PIE
to the sound along the water table at Transect PI is about seven months.
These travel times are representative residence times for water that
enters the shallow aquifer in developed areas near the ocean and sound.
3.2.2.3 Mater Levels
Ground-water levels in the shallow aquifer varied in response to
recharge and discharge. Water levels would rise rapidly in response to
recharge from precipitation and fall gradually at other times due to
discharge. The long-term water-level recession rate due to discharge is
about 0.03 ft/day at well P2C1. Discharge includes seepage of water to
the ocean and sound, transpiration by vegetation and evaporation. Water-
level variations in Well P2C1, located in Pine Knoll Shores and generally
representative of recharge and discharge conditions in the Atlantic
Beach/Pine Knoll Shores study area, are presented in Figure 3-19.
Evapotranspiration noticeably affected water levels in Pine Knoll
Shores at well P2C1 during the growing season. Water-level declines
would steepen during daylight hours in response to the demands of eva-
potranspi ration. These effects were evident in August 1984, when data
collection began, and lasted until late October 1984. They became evi-
dent again in April 1985.
Water levels in some of the other shallow wells within Pine Knoll
Shores appear to behave similarly to well P2C1. Diurnal fluctuations in
water levels that could be attributed to evapotranspirati on were observed
in these wells during 24-hour measurements in August 1984, whereas there
were no apparent diurnal fluctuations in water levels during 24-hour
measurements in February 1985.
Water-level declines in Pine Knoll Shores during August were 0.01 to
0.02 ft/day greater than those that occurred during the non-growing
season. This added decline is largely the result of transpiration by
vegetation and amounts to 0.7 to 1.5 inches per month.
Diurnal water-level fluctuations that could be attributed to eva-
potranspi ration were not apparent in August 1984 or February 1985 from
24-hour measurements made in wells located in Atlantic Beach. The scarc-
ity of vegetation in Atlantic Beach probably accounts for the lack in
diurnal water-leVel fluctuations during the growing season.
The influence of tidal fluctuations on water levels appears to be
confined to areas adjacent to the ocean and sound. Water-level
variations of 0.1 to 0.2 feet, probably caused by tidal influences, were
observed in wells adjacent to the ocean and sound during 24-hour periods
in August 1984 and again in February 1985. Water levels in the other
wells at these times did not appear to be influenced by tidal fluc-
tuations.
3-36
-------
(4.00) Total rainfall for the day when the total exceeds the scale
Dashed line represents missing water level record
Figure 3-19. Relation between ground-water levels and precipitation in the Atlantic Beach/
Pine Knoll Shores study area.
-------
3.2.2.4 Net Ground-Water Recharge
Net recharge to the shallow aquifer is the difference between water
gains and water losses at the water-table surface. Water 9a]ns occur as
infiltration from precipitation and wastewater disposal. Water losses
occur as a result of evapotranspiration. Changes in water stored in the
unsaturated zone overlying the shallow aquifer influences the net
recharge and must also be taken into account.
Net recharge along each of the transects was computed using a
monthly water budget for water gains and losses at the water-table sur-
face (see Section 3.1.2.4). Summaries of these computations for tran-
sects in Atlantic Beach and Pine Knoll Shores are presented in Tables 3-5
and 3-6, respectively.
In Atlantic Beach, precipitation and wastewater are both important
sources for recharge to the shallow aquifer. Precipitation accounted for
approximately 70 percent of the recharge along Transects A1 and A2 and
wastewater accounted for the remaining 30 percent.
In Pine Knoll Shores, precipitation is the major source and
wastewater is a minor source for recharge to the shallow aquifer.
Precipitation accounted for approximately 98 percent of the recharge
along Transect PI and about 88 percent of the recharge along Transect P2.
Wastewater accounted for the remainder of the recharge received along
these transects.
All precipitation was assumed to infiltrate into the soil in these
analyses. This assumption is reasonable as the soil is permeable and
little or no runoff is observed during most rains. Also, there is no
stormwater collection system in Atlantic Beach or Pine Knoll Shores to
collect and convey runoff from buildings and streets. Runoff generally
ponds in low areas and eventually seeps into the ground or evaporates.
Monthly precipitation for the analyses was determined from daily
rainfall records collected by the Atlantic Beach public works department.
Data for June, July and part of August were supplemented with that
collected by the National Weather Service at Moorehead City, located
about one mile north of Atlantic Beach.
Wastewater disposal for the analyses was assumed to be equal to
water use from public supplies. Most water used in Atlantic Beach and
Pine Knoll Shores is treated on-site and disposed of by infiltration of
the water into the ground. Also, water from private shallow wells does
not materially affect the water balance for the shallow aquifer.
Monthly wastewater disposal along the transects in Pine Knoll Shores
was estimated from the quarterly water use records for residents along
the transects. The ratio of monthly to quarterly water use, needed to
distribute water use on a monthly basis, was assumed to be the same as
that observed at Atlantic Beach.
3-38
-------
TABLE 3-5
SUMMARY OF RECHARGE COMPUTATIONS FOR TRANSECTS IN ATLANTIC BEACH^
Transect Parameter 1984 1985 Totals
ID
(inches)
June
July
Aug
Sept
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
A1
In
6.94
8.54
1.42
13.98
0.51
2.58
2.15
2.54
6.43
3.93
0.71
7.38
57.11
Iw
1.63
1.84
1.90
0.99
0.58
0.52
0.70
0.47
0.23
0.39
0.71
1.81
11.77
AS
0
0
-0.80
0.80
-0.80
0.80
0
0
0
0
-0.80
0.80
0.00
ET
5.71
6.25
2.22
3.92
1.31
1.27
1.21
0.20
0.52
1.37
1.51
5.33
30.82
W
2.86
4.13
1.90
10.25
0.58
1.03
1.64
2.81
6.14
2.95
0.71
3.06
38.06
IP
6.94
8.54
1.42
13.98
0.51
2.58
2.15
2.54
6.43
3.93
0.71
7.38
57.11
1.13
1.47
1.55
0.99
0.56
0.53
0.47
0.63
0.89
0.78
0.56
0.91
10.47
AS
0
0
-0.80
0.80
-0.80
0.80
0
0
0
0
-0.80
0.80
0.00
ET
5.71
6.25
2.22
3.92
1.31
1.27
1.21
0.20
0.52
1.37
1.51
5.33
30.82
W
2.36
3.76
1.55
10.25
0.56
1.04
1.41
2.97
6.80
3.34
0.56
2.16
36.76
^All values are reported in inches.
-------
TABLE 3-6
SUMMARY OF RECHARGE COMPUTATIONS FOR TRANSECTS IN PINE KNOLL SHORES^
Transect Parameter 1984 1985 Totals
ID
(inches)
June
July
Auq
Sept
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
PI
*P
6.94
8.54
1.42
13.98
0.51
2.58
2.15
2.54
6.43
3.93
0.71
7.38
57.11
Iw
0.06
0.07
0.07
0.05
0.05
0.05
0.05
0.03
0.03
0.03
0.03
0.05
0.57
AS
0
0
-0.80
0.80
-0.80
0.80
0
0
0
0
-0.80
0.80
0.00
ET
5.71
6.25
2.22
3.92
1.31
1.27
1.21
0.20
0.52
1.37
1.51
5.33
30.82
W
1.29
2.36
0.07
9.31
0.05
0.56
0.99
2.37
5.94
2.59
0.03
1.30
26.86
P2 Ip
Aw
AS
ET
U
6.94
8.54
1.42
13.98
0.51
2.58
2.15
2.54
6.43
3.93
0.71
7.38
57.11
0.25
0.54
0.54
0.36
0.14
0.14
0.14
0.14
0.14
0.14
0.36
0.58
3.47
0
0
-0.80
0.80
-0.80
0.80
0
0
0
0
-0.80
0.80
0.00
5.71
6.25
2.22
3.92
1.31
1.27
1.21
0.20
0.52
1.37
1.51
5.33
30.82
1.48
2.83
0.54
9.62
0.14
0.65
1.08
2.48
6.05
2.70
0.36
1.83
29.76
^All values are reported in inches
-------
Monthly soil moisture changes and monthly evapotranspiration used in
the analyses were computed using methods outlined by the EPA (Fenn et
al., 1975). These methods are described in Appendix G.
3.2.2.5 Water Quality
Ground-water samples were taken periodically for the analysis of
selected parameters (Table 3-7). Water samples were collected in July
1984, October 1984, January 1985 and April 1985 along the designated high
population density transects Al and A2, in July 1984 and January 1985
along Transect PI, the designated medium population density transect, and
in January 1985 along the designated low population density transect,
Transect K3.
Water samples were collected with two objectives in mind. One
objective was to define the relationship between saltwater and freshwater
in the shallow aquifer. The second objective was to define the current
impact of wastewater disposal on the quality of water in the shallow
aquifer.
Additionally, water samples were collected along Transects Al and A2
in September 1984 to aid in assessing the effects of hurricane Diane on
the ground-water system.
3.2.2.5.1 Relationship Between Freshwater and Saltwater
Measured chemical properties of the ground water used to aid in
defining saltwater intrusion into the shallow aquifer included sodium
concentration, chloride concentration, total dissolved solids con-
centration and specific conductance. Sodium and chloride are the major
constituents in saltwater. Total dissolved solids measures all solids in
solution in the water, including sodium and chloride. Specific conduc-
tance measures the ability of water to conduct an electrical current, and
generally increases with an increase in total dissolved solids content in
the water.
Elevated total dissolved solids concentrations had a strong correla-
tion with elevated sodium and chloride concentrations in water from the
shallow aquifer along both transects in Atlantic Beach, and is a good
indicator of saltwater intrusion into the aquifer. The total dissolved
solids content in the water was used to determine the presence of salt-
water and freshwater in the shallow aquifer.
Elevated specific conductances also correlated well with increased
sodium and chloride concentrations in water from the aquifer.
Variations in the total dissolved solids content of water in the
shallow aquifer at Atlantic Beach are apparent (Figures 3-20 and 3-21).
Freshwater generally exists at the surface of the shallow aquifer.
However, the total dissolved solids content of the water increases with
depth, indicating an increased influence from saltwater intrusion into
the aquifer. At three of the four well sites along Transect Al, the
total dissolved solids content of the water increases to brackish levels
below the depth of the shallowest monitoring wells (Table 3-7). Only
3-41
-------
TABLE 3-7
SUMMARY OF CROWD-WATER QUALITY ANALYSES FOR ATLANTIC BEACH/PINE KNOLL SHORES*1)
Well
ID
Saapling
date
Sodiua
Chlo-
ride
Total
dis- nia
solved (ag/1
solids as N)
Nitrate
plus
nitrite
(ag/1
as N)
Alkalin-
ity (ag/1
as CaCO*)
Hardness
(ag/1
CaCOi)
as
NBAS
(¦a/1)
Ortho-
phosphate
(ag/1 as P)
Temper-
ature
*C
Specific
conductance
(twhos/ca)
PH
(s.u.)
Fecal
coliforn
(colonies
per 100/
ml)
Atlantic Beach
Transect A1
A1A1
A1A3
A1B1
A1B3
A1C1
A1C3
153ul84
36
75
390
0.02
<0.05
148
158
0.10
<0.01
23
486
7.60
36
17Sep64
35
67
318
<0.01
0.25
197
586
<0.02
0.37
25
470
6.73
<1
180ct84
33
47
320
0.50
<0.05
166
270
<0.02
0.51
20
495
7.10
<1
193an85
45
50
284
0.11
<0.05
166
210
<0.02
0.45
17
400
7.38
<1
11Apr85
34
59
286
2.11
<0.05
137
435
0.04
1.41
17
400
7.62
<1
153ul84
354
540
1248
0.56
<0.05
248
576
0.10
1.41
22
1940
7.79
28
17Sep84
397
640
1348
0.71
0.36
268
720
<0.02
0.36
23
2150
7.09
<1
180ct84
335
493
1208
1.02
<0.05
246
430
<0.02
0.67
17
1950
7.55
1
193an85
822
761
1450
0.62
<0.05
264
315
<0.02
0.16
21
5000
7.74
<1
1lAprSS
274
637
1404
1.77
<0.05
253
333
<0.02
0.16
19
1580
7.78
<1
153ui84
4
6
240
0.28
0.47
104
150
0.11
<0.01
25
23 2
7.91
<1
17Sep84
5
12
555
<0.01
0.29
102
420
<0.02
0.03
25
215
7.04
<1
180ct84
6
11
252
<0.01
<0.05
198
225
<0.02
0.20
20
375
7.20
<1
193a n85
51
16
162
0.16
<0.05
142
155
<0.02
0.10
16
240
7.72
2
11Apr85
21
37
273
0.52
<0.05
157
232
<0.02
0.07
18
410
7.61
<1
153ul84
12
17
308
<0.01
0.12
135
550
0.09
1.41
23
335
7.77
<1
17Sep84
66
127
527
0.13
0.67
153
880
<0.02
0.22
23
700
6.96
<1
180ct84
241
441
278
0.74
<0.05
177
620
<0.02
0.42
18
1750
7.23
<1
193an85
1068
925
1968
1.06
<0.05
216
595
<0.02
0.31
22
5000
7.64
<1
11Apr85
436
970
2124
1.81
<0.05
226
611
<0.02
0.72
20
3300
7.66
<1
153ul84
21
17
336
0.10
0.07
139
210
<0.02
0.13
24
366
7.26
56
17Sep84
16
13
214
<0.01
0.16
140
820
<0.02
0.16
25
310
6.60
<1
180ct84
16
20
244
0.51
<0.05
173
470
<0.02
0.54
21
350
7.15
<1
193an85
65
22
206
0.45
<0.05
200
260
<0.02
0.38
17
350
7.52
<1
11Apr85
14
24
229
0.42
<0.05
151
278
<0.02
0.22
19
362
7.48
<1
153ul84
22
44
404
0.05
<0.05
252
524
<0.02
1.02
22
620
7.44
>250
17Sep84
36
43
335
0.21
0.55
220
2100
<0.02
<0.01
23
490
6.66
<1
180c 18*»
18
26
346
0.86
<0.05
194
625
0.04
1.70
20
530
7.25
<1
193an85
96
76
398
0.18
<0.05
214
245
<0.02
0.10
22
700
7.71
<1
11Apr85
56
96
456
1.64
<0.05
222
546
<0.02
0.62
20
750
7.52
<1
-------
TABLE 3-7
(continued)
SUMMARY OF GROUND-VATER QUALITY ANALYSES FOR ATLANTIC BEACH/PIKNOLL SHORES
Fecal
colifon*
(colonies
per 100/
¦1)
Veil
ID
Sampling
date
SodiiM
Total
dis- nia
Chlo- solved (ag/1
ride solids as N)
Nitrate
plus
nitrite
(¦g/1
as N)
Alkalin-
ity (ag/1
as CaCO^)
Hardness
(¦g/1 as NBAS
CaOO*) (wn/1)
Ortho-
phosphate
(¦g/1 as P)
Temper-
ature
*C
Specific
conductance
(mhos/cw)
P«
(s.u.)
Atlantic Beach
Transect A1
AW1
A102
OJ
I A103
Co
153ul84
72
46
662
1.53
<0.05
369
330
17Sep84«
82
48
509
2.01
0.09
353
366
180ct84
84
37
580
4.54
<0.05
385
340
193aoS5
135
41
562
8.68
<0.05
432
355
11Apr85
76
40
501
5.49
<0.05
373
287
153ul84
467
830
1667
0.61
<0.05
217
350
17Sep84*
380
700
1318
0.46
0.62
221
980
180ct84
414
687
1498
1.14
0.44
218
410
193an85
455
715
1520
0.39
0.06
223
310
11Apr85
282
1070
1400
1.25
<0.05
225
361
153ul84
576
1250
2830
0.95
<0.05
252
2300
17Sep84*
102
138
418
0.24
0.88
220
228
180ct84
297
536
512
1.56
<0.05
206
1495
193an85
802
1999
4060
2.85
<0.05
252
1055
11Apr85
1110
2550
5082
9.10
0.23
266
2759
0.11
<0.02
0.19
0.05
0.26
0.03
<0.02
0.09
<0.02
0.12
0.18
<0.02
0.04
<0.02
<0.02
1.11
0.39
2.60
2.29
2.70
0.17
0.16
0.39
0.26
0.33
3.56
0.45
0.66
0.13
6.30
25
25
21
19
19
24
23
17
21
20
23
22
17
24
20
850
750
880
950
880
2910
2010
2530
2300
2410
4320
490
5900
12500
6600
7.14
6.39
6.74
6.88
6.92
7.25
7.33
7.13
7.80
7.75
7.86
6.73
6.82
7.56
7.47
13
>740
>730
<1
<1
22
>170
4
<1
<1
<1
>450
4
<1
<1
Transect A2
A2A1
A2A3
A2A4
153ul84
17Sep84
180ct84
193an85
11Apr85
153ul84
17Sep84
180ct84
193an85
11Apr85
153ul84
17Sep84
180ct84
193an85
11ApM5
21
33
310
<0.01
0.17
174
340
<0.02
0.06
24
448
7.81
22
31
317
0.07
0.98
203
300
<0.02
<0.01
23
410
7.03
24
26
274
0.14
0.29
187
250
0.05
0.01
20
365
6.60
65
32
234
0.14
0.12
182
216
<0.02
0.11
19
355
7.71
26
37
286
0.51
<0.05
191
211
<0.02
0.13
18
459
7.67
46
60
474
0.21
<0.05
317
374
<0.02
0.41
21
810
7.84
50
33
647
1.43
1.01
271
224
0.05
<0.01
23
680
6.97
48
56
422
2.05
0.14
281
308
0.08
0.07
18
680
6.74
97
55
370
1.23
0.13
272
263
<0.02
0.11
20
680
7.54
43
52
408
6.10
<0.05
280
343
0.26
0.52
20
710
7.59
2510
4800
10934
1.43
<0.05
391
1700
<0.02
0.03
23
7500
7.67
2940
4474
9612
5.98
1.05
366
296
<0.02
0.42
22
13000
6.83
2581
4428
9596
6.11
<0.05
347
1400
0.06
0.43
17
13500
6.60
1274
4624
9246
12.50
<0.05
387
1410
<0.02
0.30
-
13000
7.40
1280
5000
9584
17.20
<0.05
378
1519
0.07
0.37
18
12100
7.49
-------
TABLE 3-7
(continued)
SUMMARY OF GROUND-WATER QUALITY ANALYSES FOR ATLANTIC BEACH/PINE KNOLL SHORES
Nitrate
Fecal
Total
Anmo-
plus
coliform
dis-
nia
nitrite
Alkalin-
Hardness
Ortho-
Temper-
Specific
(colonies
Well Sampling
Chlo-
solved
(«g/l
(«g/l
ity (mg/1
(ing/1 as
MBAS
phosphate
ature
conductance
pH
per 100/
ID date
Sodium
ride
solids
as N)
as N)
as CaCOi)
CaCO,)
(mq/1)
(mg/1 as P)
*C
(Mnhos/cm)
(s.u.)
ml)
Atlantic Beach (cont'd)
Transect A2
A2B1 153ul84
21
32
362
0.38
<0.05
217
216
<0.02
0.10
27
550
7.51
<1
17Sep84*
22
54
330
0.38
0.57
178
300
<0.02
<0.01
24
420
7.16
>6000
180ct84
19
26
556
0.66
<0.05
212
265
0.04
0.21
20
470
6.42
5
193a n85
83
34
342
0.78
<0.05
247
259
<0.02
0.30
17
430
7.25
3
1IApr85
27
27
338
1.20
<0.05
273
278
0.07
0.31
20
580
7.23
<1
A2B3 153ul84
30
59
346
0.38
<0.05
256
252
0.10
0.01
25
700
7.68
<1
17Sep84*
29
77
386
0.77
0.05
228
520
<0.02
<0.01
22
490
7.34
>1400
180ct84
30
45
308
1.15
<0.05
267
370
0.06
0.38
20
650
6.61
>40
193an85
77
41
320
0.31
0.35
273
261
<0.02
0.12
20
650
7.38
<1
11Apr85
40
40
360
1.77
<0.05
266
361
0.07
0.44
21
640
7.55
<1
A2B4 153ul84
490
1040
1984
1.23
<0.05
326
2640
0.11
<0.01
23
2840
7.67
<1
17Sep84»
70
81
461
0.31
0.37
213
328
0.12
0.42
23
620
7.10
>1150
180ct84
289
452
1248
2.84
<0.05
277
390
0.06
0.21
17
2100
6.71
2
193an85
592
878
1758
0.45
<0.05
314
409
0.02
0.02
22
2920
7.41
<1
1 IApr85
29
921
1947
8.30
1.24
298
500
0.06
0.12
20
3320
7.49
<1
A2C1 153ul84*
28
36
582
0.73
<0.05
356
418
0.06
0.29
24
898
7.42
>150
17Sep84*
36
76
651
0.05
0.25
324
208
0.15
0.07
24
780
6.94
>24900
180ct84
44
45
662
1.25
<0.05
399
510
0.05
0.12
20
1050
6.44
>2000
193an85
80
38
650
0.18
<0.05
491
543
<0.02
0.16
16
910
7.06
>2
11Apr85
142
33
635
4.30
<0.05
453
511
0.07
0.36
17
920
7.30
<1
A2C3 153ul84*
90
77
604
0.33
<0.05
435
418
0.07
0.41
23
1000
7.71
>35800
17Sep84*
64
52
546
0.54
0.54
358
308
0.04
0.04
23
750
7.41
>36800
180ct84
96
52
974
1.08
<0.05
458
365
0.05
0.15
18
890
6.80
>3000
193an85
337
76
698
0.98
<0.05
547
291
0.02
0.12
20
1100
7.64
>6
11Apr85
89
62
684
1.25
0.49
480
287
0.13
0.16
18
1100
7.72
<1
A2C4 153ul84*
1720
3020
5172
1.05
<0.05
447
650
0.14
0.01
22
6500
7.74
>60
17Sep84*
200
330
725
0.86
0.32
200
204
0.03
<0.01
22
1120
7.75
>4120
180ct84
659
919
1762
3.10
<0.05
260
410
0.06
0.13
18
4060
6.56
>600
193an85
753
1906
3822
1.05
0.53
362
620
0.07
0.12
22
7000
7.67
<1
11Apr85
95
1820
3298
1.16
0.06
293
463
0.14
0.21
19
7900
7.64
<1
-------
TABLE 3-7
(continued)
SUMMARY OF GROUND-WATER QUALITY ANALYSES FOR ATLANTIC BEACH/PINE KNOLL SHORES
SampU^)
date
Pine Knoll Shores
Transect P1
P1A1
P1A2
P1A3
P1B1
P1C1
P1C2
P1C3
P1C4
P101
P1E«
P1E2
P1E3
163ul84
193an85
163ul84
193an85
163ul84
193an85
163ul84
2G3an85
163ul84
193an85
163ul84
193an85
163ul84
193an85
163ul84
193an85
163ul84
203an85
163ul84
203an8i
163ul84
203an85
160ul84
203an85
Sodium
15
74
48
111
37
90
34
108
14
67
34
94
27
108
1820
208
13
83
13
83
27
90
24
94
29
48
41
60
73
80
83
80
30
43
18
144
52
62
34
148
23
32
22
45
61
52
52
60
Total
dis-
solved
solids
232
306
276
264
428
454
396
438
276
342
814
742
272
314
656
540
196
190
140
318
188
226
230
306
Ammo-
nia
(mg/1
as N)
0.21
0.16
0.29
0.14
<0.01
0.79
<0.01
0.55
1.12
4.58
0.19
10.70
0.96
0.78
<0.01
1.28
<0.01
0.31
<0.01
0.28
<0.01
0.12
0.19
0.54
Nitrate
plus
nitrite
lug/1
as N)
<0.05
<0.05
<0.05
<0.05
<0.05
0.13
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
Alkalin-
ity («g/l
asCaCOi)
109
132
148
159
239
275
183
239
174
212
309
403
178
189
256
262
122
88
109
164
109
118
178
205
Hardness
(mg/1 as MBAS
CaCOrt) (mq/1)
174
214
350
120
290
277
312
296
250
230
524
442
256
212
194
254
196
127
170
212
220
176
226
216
0.09
<0.02
<0.02
0.02
0.04
0.05
0.11
<0.02
0.21
<0.02
0.10
0.05
<0.02
0.02
0.03
<0.02
0.09
0.02
0.06
0.02
0.03
<0.02
0.09
0.03
Ortho-
phosphate
(wo/1 as P)
0.06
0.18
0.74
0.09
<0.01
0.09
0.20
0.36
0.67
0.81
1.05
1.02
0.32
0.16
0.16
0.24
2.81
6.34
0.56
1.25
1.14
0.59
0.37
0.24
Temper-
ature
*C
23
19
22
20
22
19
22
18
23
15
22
18
22
18
20
18
22
18
22
17
21
19
21
18
Specific
conductance
(mhos/cm)
Fecal
coliform
(colonies
per 100/
ml)
355
7.60
<1
400
7.74
<1
400
7.84
<1
400
7.96
<1
650
7.48
<1
700
7.51
>10
530
7.50
<1
495
7.40
1
375
6.32
1
350
6.07
13
990
6.90
<1
1100
6.85
<1
430
7.37
<1
435
7.28
<1
1040
7.65
<1
1000
7.69
<1
245
6.59
<1
190
6.55
<1
275
6.78
312
340
6.71
<1
345
7.74
<1
360
7.61
<1
421
7.49
<1
445
7.55
<1
-------
TABLE 3-7
(continued)
SIMHARY OF GROUND-WATER QUALITY ANALYSES FOR ATLANTIC BEACH/PINE KNOLL SHORES
Nitrate
Fecal
Total
Ammo-
plus
coliform
dis-
nia
nitrite
Alkalin-
Hardness
Ortho-
Temper-
Specific
(colonies
Well
Sampling
Chlo-
solved
(mg/l
(mg/1
ity (mg/1
(mg/1 as
NBAS
phosphate
ature
conductance
pH
per 100/
10
date
Sodium
ride
solids
as N)
as N)
as CaCO?)
CaCO,)
(mq/1)
(mg/1 as P)
•c
(imhos/cm)
(s.u.)
ml)
Pine Knoll Shores
(cont'd)
Transect P2
P2A1
203an85
166
54
540
0.28
<0.05
348
364
0.02
0.50
19
760
7.23
<1
P2A2
203an85
427
460
1206
0.47
<0.05
372
465
<0.02
4.63
20
2000
7.46
<1
P2A3
203an85
420
328
892
1.35
<0.05
265
486
<0.02
1.71
20
1290
7.71
<1
P2B1
203an85
85
43
188
0.57
0.33
59
127
<0.02
0.78
17
270
7.65
<1
P2C1
203an85
98
48
306
0.28
<0.05
159
221
<0.02
0.50
6.86
<1
P2C2
203an85
126
141
648
5.00
<0.05
296
414
0.03
1.01
19
890
6.95
<1
P2C3
203an85
130
92
492
1.30
<0.05
219
329
0.04
0.96
19
720
7.31
2
P2C4
203an85
343
272
922
5.38
<0.05
414
207
0.02
0.12
19
1500
7.63
<1
P2D1
203an85
80
34
116
5.64
<0.05
55
207
0.02
3.76
19
200
6.74
<1
P2E1
203an85
84
71
390
0.22
<0.05
264
273
0.02
1.59
18
380
6.73
<1
P2E2
203an85
9
48
306
0.52
<0.05
284
519
0.02
1.87
19
440
7.45
<1
P2E3
203an85
1011
5044
10638
3.45
<0.05
282
1170
0.03
t.18
-
27500
7.61
<1
^Aii analyses are in milligrams per liter (mg/1) unless otherwise noted.
~Evidence of flooding at well site.
-------
20'.
SEA LEVEL.
-20'.
-40'.
-60'.
-SOI
-100:
-120'.
BOQUE
SOUND
•j
CD
UJ
>
Z
<
0
O
0
z
UJ
O
<
UJ
h>
S
H
c0
-J
2
cc
CO
O
<
<
UJ
h
55
ATLANTIC
V OCEAN
At* —
SOO FEET
Well Site D Well Site C Well Site B Well Site A
20'
.SEA LEVEL
.-20'
.-40'
-60'
-80'
-100'
.-120'
lua concentration. Nunoer m
*"» parenthesis represents observed
2| concentration when the vertical
1 scale 1s exceeded
Figure 3-20. Variation 1n total dissolved solids concentration alonq Transect Al.
3-47
-------
20.
SEA LEVEL.
-so:
-40:
-601
-so:
-100:
-1201I
-140'.
-160'.
BOQUE
SOUND V f
>
0
UJ
a
>
>
<
z
0
O
UI
s
0
3
»-
0.
I
C4
IP
MaONOJPMAM
JASONOJFMAM
-20'
r40'
-60'
.-80'
-100'
120'
r140'
L-160'
EXPLANATION
Generalized water table
Hell site showing location
of sampling Intervals
TDS concentration. Number
1n parenthesis represents
observed concentration
when the vertical scale
1s exceeded.
Figure 3-21.
Variation in total dissolved solids concentration along
Transect A2.
3-48
-------
well site A1C shows no strong influence from saltwater intrusion.
Freshwater generally exists in the shallow aquifer at Transect A2, but
brackish to saline water was found in the underlying confining beds. At
well A2A4, completed in the confining beds, total dissolved solids con-
centration at times exceeded the saline level. Definitions for fresh,
brackish and saline waters are given in Section 3.1.2.5.1.
At Pine Knoll Shores, freshwater generally exists in the shallow
aquifer. No strong influence from saltwater intrusion was evidenced
along Transect PI. Elevated total dissolved solids contents were
observed at two wells along Transect P2 (Table 3-7). The total dissolved
solids content slightly exceeds the brackish concentration level at well
P2A2 adjacent to the ocean. Saline water exists at well P2E3 adjacent to
Bogue Sound.
3.2.2.5.2 Effects of Wastewater Disposal
Measured chemical properties of the ground water used to aid in
defining the effects of wastewater disposal to the shallow aquifer
included nitrate plus nitrite concentration (nitrate/nitrite), ammonia
concentration, orthophosphate concentration, methylene blue active
substances (MBAS) concentration, and fecal coliform concentration.
Nitrate, nitrite, ammonia and orthophosphate are common nutrients present
in wastewater. MBAS are substances used in detergents and that do not
occur naturally in the environment. Fecal coliform are a group of bac-
teria which come from the intestines of mammals and may be found in
wastewater and sometimes in storm water runoff.
Nitrate/nitrite and ammonia, reported in mg/1 as nitrogen (N), were
detected in ground water at each of the transects in the Atlantic
Beach/Pine Knoll Shores study area (Table 3-7). Nitrate/nitrite con-
centrations showed no obvious trend during the study period except that
significantly elevated nitrate/nitrite concentrations were measured at
most wells in Atlantic Beach following hurricane Diane. Amnionia con-
centrations typically increased with depth, with the exception of well
sites AID and PIC, where most high readings were obtained near the sur-
face of the aquifer. Variations in nitrate/nitrite and ammonia con-
centrations along Transect A1 and A2 are shown in Figures 3-22, 3-24 and
3-23, 3-25, respectively.
Nitrate, nitrite and ammonia are contaminants which are frequently
found in ground water. The presence of these constituents in the shallow
ground water could, therefore, be indicative of the impact of wastewater
disposal. The highest observed levels of nitrate/nitrite and ammonia
were 1.24 mg/1 and 17.20 mg/1, respectively. The drinking water standard
for nitrates is 10 mg/1 as nitrogen (N). There are no drinking water
standards for ammonia.
Orthophosphates, reported in mg/1 as phosphorus (P), were also
detected in ground water along all transects in Atlantic Beach and Pine
Knoll Shores (Table 3-7). Along Transect Al, higher concentrations
appear to be at depth, with the exception of well site AID, where the
highest concentrations are nearer the surface. Along Transect A2, high
and low concentrations appear equally distributed with depth. Along Pine
3-49
-------
20'
SEA LEVEL.
-201
-40'.
-60'.
-SO!
-100:
-120'.
BOQUE £
SOUND
V_ f
ATLANTIC
OCEAN
D3:li
500 FEET
Well Site D
uxtf ® ^
2 7»
CD
0»
E - Ml.,?,,?.
Z
o
p
<
a
H
Z
UJ
O
z
o
o
D2
too.
.76.
M.
M-
0
03
• * I
1 V III I V I1
JAtOMDJPMAM
Well Site C
too-
C1
.!*•
M'
.»
f I* » •
too-
C3
.75-
.#0
1
M-
I
• i* • •
— * " ' * ' * " * ' '
I0O<
«
M-
0
Well Site B Well Site A
B1
¦ It. if. ¦i
too
w
M
.»»«
0
B3
UM-
A1
1
• i* • «
too
A3
JO-
|
J*
.20'
.SEA LEVEL
.-20'
.-40'
.-60'
.-80'
.-100'
.-120'
EXPUMTIOW
Z Stntrdlxttf iNtor tabic
¦jjj Mil tltt showing location
*1 of M«p11ng Intervals
I Nttitte/IHtHto concentration
_ Nltrato/Wtrltt not dotoetod
In analysis
Figure 3-22. Variation 1n nitrate plus nitrite concentration along
Transect A1.
3-50
-------
2o:
SEA LEVEL.
-20:
-40:
-so:
-ao:
-100'.
-120:
-140'.
-1S0'.
80QUE
SOUND /
0
ATLANTIC
OCEAN V
_20'
SEA LEVEL
SOO FEET
—I
Well Site C
09
W
01
E
O
<
OC
H
Z
UJ
o
too-
.ts.
¦to-
>»•
»
CI
r*rr*r-
.7*-
.S0-
M-
0-
C3
wo.
.r»
41
0
rJWr
C4
illnliili
JAtOIUMMtAM
LImiIom aqulfor
Well Site B
.-20'
.-40'
.-SO'
.-80'
1-100'
.-120'
r140*
-ISO'
wo.
.?•
.#0-
.IS
0
B1
»lt 1 it nt 1
WO-
jr#
M
.«»
0'
B3
JO-
M
ft,
B4
I- •
ill I IIHW
JAtONOJPMAM
Well Site A
¦
«
a
At
Ix *
A3
4
4
ft
1
3f
EJffLAHATiqW
General tied water table
Well site showlus location
of smpllng Intervals
Nitrate/Nitrite concentration.
Nueber In parenthesis
represents observed
concentration when the
vertical scale Is exceeded
*1trate/N1tr1te not detected
1n analysis
Figure 3-23. Variation In nitrate plus nitrite concentration along Transect A2.
3-51
-------
2o:
SEA LEVEL.
-20:
-40'.
-60'.
-80:
-1001
-120'.
BOGUE
SOUND
ATLANTIC
V OCEAN
AT ~
500 FEET
I
CO
CO
*«.
a>
E
Z
O
F
<
QC
I-
z
Hi
o
z
o
o
Well Site D Well Site
too
.78.
.60
.25
0
(2.01)
3
too-
.78'
40
.26.
0
D2
¦»1»»
too-
.76.
.60
J26'
0
D3
JASONDJPMAM
Well Site B Well Site A
too
.76'
jSO
.26
0'
B3
too-
78
.80
.28
0
A3
EXPLANATION
2 Generalized water table
-I Well site showing location
"I of sampling intervals
U)| Anmonla concentration. Number 1n
ClJ parenthesis represents observed
concentration when the vertical
v scale Is exceeded
* Ammonia not detected 1n analysis
20'
SEA LEVEL
.-20'
-40'
.-60'
.-80'
.-100'
L-120'
Figure 3-24. Variation in ammonia concentration along Transect A1.
3-52
-------
201
SEA LEVELJ
-20U
-40J
-eoll
-801
-100'J
-120 J
-140'J
- 160'J
BOQUE
SOUND V f
0
L.
ATLANTIC
OCEAN V
|B4
: ;»g:
600 FEET
.20'
Lsea level
L-20'
k-4 0'
L-eO'
-80'
blOO'
-120'
-140'
.-180'
Limestone aquifer
Well Site C Well Site B
Well Site A
CO
CO
o>
E
Z
o
<
cc
H-
Z
Ul
o
z
o
o
too
.tM
«o
0
C1
C3
tooJ
.78
Mi
.2#
0
too-
.r»
.so
0.
ll
C4
E
jasondjfmam
explanation
X Generalized water table
til Hell site showing location
-------
Knoll Shores transects, the highest orthophosphate concentrations appear
to be at an intermediate depth, with the lowest readings occurring deeper
in the aquifer. Variations in orthophosphate concentrations along
Transects A1 and A2 are shown in Figures 3-26 and 3-27, respectively.
The presence of phosphorous compounds in the ground water is typi-
cally a result of wastewater disposal. The usual sources for phosphorous
are organic waste products and phosphate detergent residues. The highest
observed level of orthophosphate was 6.34 mg/1. There are no drinking
water standards for orthophosphates.
MBAS were detected at most well sites during the study but were
found more consistently and generally in higher concentrations during the
July 1984 and April 1985 samplings (Table 3-7). These observations
probably reflect the impact on the shallow aquifer resulting from
increased wastewater disposal during the spring and summer months. The
presence of MBAS in the deepest wells indicates that wastewater has
penetrated the entire thickness of the shallow aquifer and has also
penetrated the confining beds underlying the aquifer. Variations in MBAS
concentrations along Transects A1 and A2 are shown in Figures 3-28 and
3-29, respectively.
The highest MBAS concentration detected at Atlantic Beach and Pine
Knoll Shores was 0.26 mg/1. The recommended secondary drinking water
standard for MBAS is 0.50 mg/1. The source of MBAS in wastewater is
synthetic foaming agents present in modern detergents.
Fecal coliform were found in 40 of the 126 ground-water samples
collected in Atlantic Beach and Pine Knoll Shores. The fecal coliform
detected in 27 of these samples may have reflected contamination of those
wells by surface flooding. Fecal coliform detected in the remaining 13
samples are probably reflecting the presence of domestic wastewater in
the ground water.
Very high levels of fecal coliform were noted at well site A2C in
July 1984 and at well sites AID, A2B and A2C in September and October of
1984 (Table 3-7). There was evidence that well site A2C had been flooded
prior to both the July and September samplings and that well sites AID
and A2B were flooded prior to the September sampling. The high fecal
coliform counts at these well sites are probably related to the flooding.
Steps were taken to prevent further contamination of the well sites prior
to continued sampling, although residue contamination was evidenced at
most of the well sites in October.
Fecal coliform, probably resulting from wastewater disposal, were
detected at some well sites in Atlantic Beach and Pine Knoll Shores
during the course of the study (Table 3-7). Fecal coliform were detected
in water samples from wells A1A1, A1A3, A1C1, A1C3 and P1E1 in July 1984
and in water samples from wells P1A3 and P1C1 in January 1985. The
highest fecal coliform count observed, outside those at well sites AID,
A2B and A2C, was 312 col/100 ml in July 1984 at well P1E1 in Pine Knoll
Shores. Variations in fecal coliform along Transects A1 and A2 are shown
in Figures 3-30 and 3-31, respectively.
3-54
-------
20'.
SEA LEVEL.
-20'.
-40'.
-60'.
-801
-1001
-120'J
BOGUE
SOUND
ATLANTIC
V OCEAN
A1"~
o
L.
500 FEET
I
Well Site D Well Site C Well Site B Well Site A
a
E
<
ac
i-
UJ
O
z
o
o
too-
.78-
,60-
.28-
0.
100-
,76'
.60
.26.
0<
D1
u
D2
too-
.76.
JO.
.26.
0
D3
JASONDJFMAM
100'
,76'
AO'
.28-
0
C1
100'
.76'
.60
.26
0
C3
*-r-
100-
.76'
.60'
.26'
0
B1
too
.76'
J50
.26
0
B3
ix
EXPLANATION
Generalized water table
Well site showing location
"i of sampling intervals
Si
oil
Orthophosphate concentration. Number
1n parenthesis represents observed
concentration when the vertical
scale 1s exceeded
Orthophosphate not detected 1n
analysis
.20'
.SEA LEVEL
.-20'
-40'
.-60'
-80'
-100'
.-120'
Figure 3-26. Variation in orthophosphate concentration along Transect A1.
3-55
-------
201
sea level.
-20:
-40:
BOGUE
SOUND V
-eo:
-80:
-100".
¦120:
-1401
¦160'J
0
c.
.20'
SEA LEVEL
.-20'
.-40'
.-60'
-80'
500 FEET
Well Site C
Limestone aquifer
Well Site B
<0
CO
o»
E
z
o
p
<
QC
K-
Z
UJ
o
z
o
o
too
.78*
.80
.28H
0
C1
11 > ll 111 111
100.
.75'
.80
.28'
0
too-
.78
.60'
26-
0.
C3
¦ tIiill ill
C4
JASONDJFMAM
Well Site A
too-
.78-
.80'
.26'
0-
100
.78
J80
.28'
0'
too-
.78-
.60-
28-
0.
B1
l.iU.I
B3
B4
k
JASONDJFMAM
r 100'
-120'
r140'
L-180'
EXPLANATION
Generalized water table
Hell site showing location
of sampling intervals
Orthophosphate
concentration
# Orthophosphate not
detected In analysis
Figure 3-27. Variation 1n orthophosphate concentration along Transect A2.
3-56
-------
20'
SEA LEVELj
-20'J
-40'J
-60'J
-80j
-100 J
BOGUE
SOUND
ATLANTIC
V OCEAN
A1X =
• 120 J
500 FEET
1
Well Site 1> Well Site C Well Site B Well Site
20'
Lsea level
L-20'
.-40'
L-60'
L-80'
L-loo'
-120'
.00'
C1
401
B1
.so*
.60'
.40-
,40"
.30-
.30-
.20'
.20-
.10-
.10-
I
* #* ~ #
| #* # *
.001
C3
.601
B3
.60-
•SO'
.40-
.401
.30'
.30-
.20-
.20-
.10'
.10-
« * *
1 #* * *
EXPLANATION
Generalized water table
Well site showing location
of sampling Intervals
MBAS concentration
MBAS not detected 1n analysis
Figure 3-28. Variation in MBAS concentration along Transect Al.
3-57
-------
20'
SEA LEVEL.
-201
-401
-60:
-so:
-100'.
-1201
-140',
-160".
BOQUE
SOUND V f
_20'
-SEA LEVEL
Limooton* aquifer
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.-40'
-60'
.-80'
r 100'
.-120'
r 140'
L-ieo'
CD
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111
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Well Site Well Site B Well Site A
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.60'
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JASOMDJPMAM
AO-
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TtTTTTTTTTn
MMNDOMAM
-EXPLANATION
X Generalized water table
Well site showing location
of sampling Intervals
MBAS concentration
MBAS not detected 1n
analysis
Figure 3-29. Variation in MBAS concentration along Transect A2.
3-58
-------
20'.
SEA LEVEL.
-201
Q
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ATLANTIC
V OCEAN
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600 FEET
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_ 20'
.8EA LEVEL
-20'
.-40'
.-60'
.-80'
•100*
r 120'
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o
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Well Site D Well Site C Well Site B Well Site A
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78.
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100-
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78-
SO'
80.
as-
as.
0-
EXPLANATION
2 Generalized water table
-I Well site showing location
&
of sampling Intervals
Fecal col 1 form concentration.
Number In parenthesis represents
mlnlnum probable concentration
wheh the vertical scale Is
exceeded
# Fecal conform not detected
1n analysis
Figure 3-30. Variation in fecal conform concentration along
Transect A1.
3-59
-------
SEA LEVEL.
BOQUE
SOUND V f
>
-J
CD
a
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z
CD
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-so:
-100'.
-1201
-140'.
0
u
ATLANTIC
OCEAN V
,-20'
SEA LEVEL
500 FEET
Well Site C
Limestone aquifer
Well Site B
--20'
-40'
.-60'
.-80'
-100'
¦120'
-140'
L- 160'
Well Site A
E
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SO
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80-
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100-
A4
78J
80-
28-
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JA80NDJFMAM
explanation
2 Generalized water table
Jj Well site showing location
M of sampling Intervals
A
Fecal conform concentration.
Number 1n parenthesis represents
minimum probable concentration
when the vertical scale 1s
exceeded
Fecal collform not
detected In analysis
Figure 3-31. Variation in fecal coliform concentration along Transect A2.
3-60
-------
Changes in ground-water quality observed between July and September
1984 are at least partially due to the impacts of hurricane Diane.
Increased nitrate/nitrite and decreased orthophosphate and MBAS levels
generally observed at the water-table surface are probably due to the
heavy rainfall received in October. Changes in water quality parameters
deeper in the aquifer, however, may be the results of previous impacts on
the shallow aquifer. A period of months are probably required for
ground-water flow to penetrate from the water-table surface to deeper
parts of the aquifer.
The impact of large wastewater volumes on ground-water quality can
be readily seen at well site AID. A drainfield at this location serves a
large condominium complex. Approximately two-thirds of the .ater used
along Transect A1 is recharged to the aquifer by this drainfield.
Ammonia, nitrate/nitrite, MBAS and orthophosphate concentrations in the
ground water at this site are among the highest observed during the
study. However, nitrate/nitrite and MBAS concentrations do not exceed
established drinking water standards. Fecal coliform are present 1n the
wells at this site, but these results are suspect due to the well site's
susceptability to flooding.
Alkalinity and hardness of the ground water were measured as overall
indicators of water quality. Alkalinity 1s a measure of the carbonate
and bicarbonate Ions in the water, with maximum levels of approximately
400 mg/1 as calcium carbonate (CaC03) considered to represent no health
problem. Hardness 1s a measure of the amount of calcium, magnesium and
iron in the water. A strong relationship between these parameters and
saltwater intrusion into the aquifer was observed from the data (Table
3-7).
Alkalinity generally Increased with depth 1n the shallow aquifer,
although exceptions can be noted (Table 3-7). The alkalinity of the
water typically ranged from 100 to 200 mg/1 at the water-table surface,
with values at well sites AID and A2C as high as 450 mg/1. Alkalinity
levels below the water-table surface ranged as high as 400 mg/1 1n Pine
Knoll Shores and as high as 550 mg/1 1n Atlantic Beach. The alkalinity
of the water at most sampling points is in the range of that generally
found 1n ground waters.
The hardness of the water also generally increased with depth in the
aquifer, although the data are not consistent, and many exceptions exist
(Table 3-7). Hardness was generally 150 to 300 mg/1 as CaC03 at the
water-table surface and 300 to 500 mg/1 as CaC03 at the base of the
aquifer. Water 1s generally considered to be hard water when the hard-
ness exceeds 150 mg/1, and very hard when 1n excess of 300 mg/1 as CaC03.
Since hardness 1n water can be easily removed with treatment, and because
hardness concentrations 1n water have not proven to be health-related, no
criterion exists for raw waters used for public water supply.
3-61
-------
3.2.3 Summary of Hydrogeologic Setting for the Atlantic Beach/Pine Knoll
Shores Study Area
The hydrogeology at Atlantic Beach and Pine Knoll Shores was studied
to identify the movement of ground water in the shallow aquifer
underlying Bogue Banks, to identify the components of recharge to the
aquifer and their magnitude, and to identify the existing quality of
ground water underlying the island. The results of this study can be
summarized as follows:
Bogue Banks is underlain by three aquifers, two of which are
known to contain freshwater.
The shallow aquifer, consisting of fine to medium sand with
lenses of silty fine sand and organic silt, extends downward
from land surface to depths of 25 to 65 feet, and is separated
from the deeper aquifers by beds of silt and clay.
Ground-water movement in the shallow aquifer is generally away
from the central part of Bogue Banks toward discharge points in
the ocean and the sound. Ground-water flow velocities at the
transects vary from less than 0.1 to about 1.6 feet per day.
Tidal fluctuations have little or no influence on ground-water
levels outside the immediate vicinity of the ocean and the
sound.
Precipitation and wastewater are both important sources of
recharge to the shallow aquifer at Atlantic Beach.
Precipitation is the major source of recharge to the shallow
aquifer at Pine Knoll Shores and wastewater is a minor source
of recharge.
The shallow aquifer generally contains freshwater but the
underlying confining beds in Atlantic Beach are known to con-
tain brackish water.
Disposal of wastewater into the shallow aquifer has had some
impact on water quality 1n the shallow aquifer.
3.3 Hvdroqeoloqv of the Surf City Study Area
3.3.1 General Hydrogeology
The ground-water system in the Surf City area has been grouped into
three aquifers (Layman, 1965). These aquifers are the shallow sand
aquifer, the limestone aquifer and the deep sand aquifer. The shallow
sand aquifer generally consists of fine sand and shells and is 30 to 50
feet thick in the study area. The limestone aquifer underlies the
shallow sand aquifer and is as much as 70 feet thick in the area. The
deep sand aquifer, of undetermined thickness, lies beneath the limestone
aquifer. A generalized hydrogeologic cross-section that extends from the
mainland to Topsail Island is shown in Figure 3-32.
3-62
-------
a. Location map for generalized hydrogeologic cross-section.
50'-
SEA LEVEL-
50-
100-
150'-
200'-
250-
300'-
350-
A'
Shallow sand aquifer
Deep sand aquifer
Geology from Layman, 1966
-------
Freshwater can be obtained from all three aquifers on the mainland
about six miles northeast of Surf City.
3.3.2 Hydrogeol og.y of the Shallow Sand Aquifer
The shallow sand aquifer was studied for this report. This aquifer
is the one most impacted by the use of on-site systems for the treatment
and disposal of wastewater. Data collected from wells drilled along
Transects SI and S3 (Figure 3-32) formed the basis for the study.
3.3.2.1 Geologic Setting
The shallow sand aquifer consists of fine sands and shells. Sandy
silt and clay, which occur between 30 and 40 feet below land surface,
form the base of the aquifer. Geologic cross-sections showing the nature
and extent of the shallow sand aquifer 1n the Surf City area are pre-
sented in Figure 3-33.
3.3.2.2 Ground-Water Occurrence and Movement
Ground water is present 1n the pore spaces of the unconsolidated
saturated deposits that underlie Topsail Island. The intergranular pore
spaces 1n the sands serve as the storage space for water 1n the shallow
sand aquifer and as pathways for water movement. The pore spaces in the
sandy silt and clay confining beds also serve to store water. However,
those ppre spaces are extremely small, making movement of water through
these deposits difficult.
Ground water 1s also present in the limestone that underlies the
unconsolidated deposits. Interconnected joints, fractures and solution
openings 1n the limestone store and transmit water freely.
Ground-water movement under Topsail Island was variable during the
study. Freshwater movement along Transect SI was generally toward the
Intracoastal Waterway, but occasionally was toward the ocean. Brackish
water movement was toward the ocean at times and toward the Intracoastal
Waterway at other times. Freshwater movement along Transect S3 was
generally downward and away from the central part of the Island toward
discharge points 1n the ocean and the Intracoastal Waterway. Brackish
and saline water moveinent was generally downward and toward the mainland
in the upper portion of the limestone aquifer along this transect;
however, vertical movement of the deeper saline water was upward at times
and downward at other times. Ground-water flow patterns 1n August 1984,
which are representative of summer conditions, are shown 1n Figure 3-34.
Flow patterns 1n February 1985, which are representative of winter con-
ditions, are shown in Figure 3-35.
Saltwater intrusion has a definite effect on water movement 1n the
shallow aquifer. Ground-water flow patterns were defined based on the
distribution of freshwater heads and environmental heads 1n the aquifer
system. Freshwater heads were used to define horizontal flow directions
and environmental heads were used to define vertical flow directions
(Lusczynskl, 1961).
3-64
-------
20*1
SEA LEVEL-
-20-
-40'-
-601
oc
o
oc
llj
>
INTRACOASTAL
WATERWAY -
UJ
UJ
>
>
S
E<
m
a
Ouj
UJ
-i
uib
K
55
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CO
SCO
o_,
a.
X _j
mj
J
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co uj
111
H*
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1
1
Fine to coarse
ATLANTIC
OCEAN
Fine to coarse
sand and shells
Silt and Clay
20'
.SEA LEVEL
-20'
-40'
.-60'
-80'J
0
L.
600 FEET
I
L-80'
40;
20:
SEA LEVEL
-20'.
-40'.
-60'.
-eo:
-100'.
-120'.
INTRACOASTAL
WATERWAY
800 FEET
ATLANTIC
OCEAN
V
Fine to coarse
sand and shells
Limestone
/
Interbedded * ,
limestone and
Z-Sandy silt
Limestone
Interbedded
limestone and
sandstone
i
EXPLANATION
Well site showing location of well
screen setting. Multiple wells are
completed at most sites
Generalized water table
~ Shallow sand aquifer
n Confining beds
lv.*l Limestone aquifer
.40'
.20'
.SEA LEVEL
-20'
-40'
-60'
-80'
-100'
-120'
Figure 3-33. Hydrogeologic cross-sections for the shallow sand aquifer
at Surf City.
3-65
-------
20't
SEA LEVEL-
-20-
-40'-
-6o;
TRANSECT S1
o
-80'i L.
INTRACOASTAL
WATERWAY ,
800 FEET
I
ATLANTIC
OCEAN
20'
SEA LEVEL
.-20'
-40'
.-60'
L-80'
TRANSECT S3
40'-
20:
SEA LEVEL.
-20'.
-40'.
-601
-80'.
-100'
-120'
INTRACOASTAL
WATERWAY
SOO FEET
J
Freshwater
head
Environmental
head
r head T
1.23 0
ntaV°-»« I
EXPLANATION
Well site showing location of well
screen setting. Multiple wells are
completed at most sites
ATLANTIC
OCEAN
V
Generalized water table
Shallow aquifer
1-40'
20'
-SEA LEVEL
.-20'
-40'
.-60'
.-80'
.-100'
.-120'
FT! Confining beds
E3 Limestone aquifer
—~Generalized ground-water flow
direction
Area of brackish to saline water
Figure 3-34. Generalized flow directions 1n the shallow sand aquifer
at Surf City on August 22, 1984.
3-66
-------
20
SEA LEVEL
-20-
-40'-
-eo:
-80'.
TRANSECT S1
INTRACOASTAL
WATERWAY -
ATLANTIC
OCEAN
—x _2_
600 FEET
__J
249
20'
.SEA LEVEL
.-20'
-40'
-60'
.-80'
401
20:
SEA LEVEL.
-201
-401
-60'.
-801
-100'.
-120'.
TRANSECT S3
INTRACOASTAL
WATERWAY
ATLANTIC
S00 FEET
I
Freshwater head
head
Environmental-—
head
1.93 {
1.69 J
EXPLANATION
Well site showing location of well
screen setting. Multiple wells are
completed at most sites
PT1 Confining beds
m Limestone aquifer
•-40'
.20'
.SEA LEVEL
-20'
.-40'
.-60'
-80'
.-100'
.-120'
•{- Generalized water table
l~I Shallow sand aquifer
\\W
Generalized ground-water flow
direction
Area of brackish to saline water
Figure 3-35. Generalized flow directions In the shallow sand aquifer
at Surf City on February 12-13, 1985.
3-67
-------
Significant recharge events would cause changes in freshwater move-
ment along Transect S3. During October 1984 and again during March 1985,
freshwater movement along this transect was generally toward the
Intracoastal Waterway. There was little movement of freshwater toward
the ocean. The October change followed hurricane Diane, which occurred
in September, while the March change followed a heavy February rainfall.
Within one month of the observed changes, freshwater flow patterns
returned to those normally observed.
The flow velocity through the shallow sand aquifer varied con-
siderably during the study. There was little or no freshwater movement
in the shallow aquifer at Transect SI during early November 1984 and
again during late January 1985. The freshwater velocity toward the
Intracoastal Waterway exceeded 1.5 ft/day between sites S3B and S3C in
September immediately following hurricane Diane and averaged about 0.7
ft/day during the study (Table 3-8). The freshwater velocity toward the
ocean between sites S3B and S3A averaged about 0.2 ft/day during the
study. Flow rates were computed using equation (1). The hydraulic con-
ductivity of the aquifer used in the computations is 84 ft/day. This
value was determined from an aquifer pumping test performed at well S3B2.
The effective porosity was computed as 0.16 by correlating precipitation
measured at Wilmington with changes in water levels observed in well S3B1
(Appendix F). Well S3B1 was equipped with a continuous stage recorder
for monitoring water levels.
The flowpath traveled by a water particle and the flow velocity of
the particle determines the time that the particle will remain in the
aquifer. The travel time from the ground-water divide to the ocean along
flowpaths at Transect S3 averages about four years, whereas the travel
time from the divide to the Intracoastal Waterway averages about 1.5
years (Table 3-8).
The shortest residence times in the shallow aquifer occur at the
water table surface near the ocean and sound. Flowpaths are shortest and
flow velocities are greatest in these areas. The travel time to the
ocean along Transects SI and S3 for a water particle entering the shallow
aquifer at well sites S1A and SIB is typically about two months. The
travel time from well site SIB to the sound along the water table at
Transect SI varies from one to four months, and the travel time from well
site S3C to the sound along the water table at Transect S3 is less than
one month. These travel times are representative residence times for
water that enters the shallow aquifer in developed areas near the ocean
and sound.
3.3.2.3 Water Levels
Ground-water levels in the shallow sand aquifer varied in response
to the tide, and to recharge and discharge. Water levels rose and fell
twice daily in response to tidal fluctuations. These fluctuations
averaged about 0.20 ft/day at well S3B1 located in the island center, and
were superimposed upon broader fluctuations that varied with recharge and
discharge rates. Water levels would rise rapidly in response to recharge
from precipitation and fall gradually at other times due to discharge.
The observed long-term water-level recession rate due to discharge is
3-68
-------
TABLE 3-8
GROUND-WATER FLOW VELOCITIES AND TRAVEL TIMES
ALONG TRANSECTS IN SURF CITY
Site Distance Mean Hydraulic Flow Travel time Remarks
between water-table gradient velocity between sites
sites elevation between sites (feet/day) (days)
(feet) (MSL) (feet/foot)
Transect S3
B 2.2 Sound side of
425 1.41 x 10"3 0.74 570 transect
C 1.6
B 2.2 . Ocean side of
280 3.57 x 10"* 0.19 1500 transect
A 2.1
3-69
-------
about 0.06 ft/day. Discharge includes seepage of water to the ocean and
Intracoastal Waterway, transpiration by vegetation and evaporation.
Water level variations in well S3B1, which are representative of recharge
and discharge conditions in the Surf City study area, are presented in
Figure 3-36.
Water level measurements were made in all wells over 24-hour periods
in August 1984 and February 1985 in an attempt to measure the impacts of
changes in evapotranspiration on the ground-water table. Diurnal water-
level fluctuations that could be attributed to evapotranspirati on could
not be distinguished from tidal fluctuations that were occurring in the
wells.
3.3.2.4 Net Ground-Water Recharge
Net recharge to the shallow aquifer is the difference between water
gains and water losses at the water-table surface. Water gains occur as
infiltration from precipitation and wastewater disposal. Water losses
occur as a result of evapotranspiration. Changes in water stored in the
unsaturated zone overlying the shallow aquifer influence the amount of
water gained by infiltration and must also be taken into account.
Net recharge along each of the transects in Surf City was computed
using a monthly water budget for water gains and losses at the water-
table surface (see Section 3.1.2.4). Summaries of these computations for
these transects are presented in Table 3-9.
Precipitation is the major source for recharge to the shallow
aquifer. Precipitation accounted for approximately 78 and 80 percent of
the recharge along Transects SI and S3, respectively. Wastewater
accounted for the remainder of the recharge received along these tran-
sects.
All precipitation was assumed to infiltrate into the soil in this
analysis. This assumption is reasonable as the soil is permeable and
little or no runoff is observed during most rains. Also, there is no
storm water collection system in Surf City to collect and convey runoff
from buildings and streets. Runoff generally ponds in low areas and
eventually seeps into the ground or evaporates.
Monthly precipitation for the analysis was determined from daily
rainfall records collected by the National Weather Service at Wilmington,
NC, located approximately 30 miles southwest of Surf City.
Wastewater disposal for the analysis was assumed to be equal to
water use. Most water used by residents in Surf City is treated on-site
and disposed of by infiltration of the water into the ground.
Monthly wastewater disposal was estimated from the quarterly water
use records for residents along the transects. The ratio of monthly to
quarterly water use, needed to distribute water use on a monthly basis,
was assumed to be the same as that observed at Atlantic Beach.
3-70
-------
JAN
1985
EXPLANATION
(6.92) Total rainfall for the day when the total exceeds the scale
Dashed line represents missing water level record
Figure 3-36. Relation between ground-water levels and precipitation in the Surf City study area.
-------
TABLE 3-9
SUMMARY OF RECHARGE COMPUTATIONS FOR TRANSECTS IN SURF CITY(1^
Transect Parameter 1984 1985 Totals
_ID June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May
SI ID 0.89 9.01 4.79 18.94 0.49 1.16 1.32 2.01 5.08 1.66 0.71 2.76 48.82
l£ 0.65 0.63 0.78 0.21 0.51 0.45 0.23 0.66 0.28 0.53 0.39 0.68 6.00
AS -0.80 0.80 -0.80 0.80 -0.80 0 0 0.80 0 -0.18 -0.62 0.00 -0.80
ET 1.69 6.02 5.59 3.76 1.29 1.16 1.32 0.28 0.71 1.84 1.33 2.76 27.75
W 0.65 2.82 0.78 14.59 0.51 0.45 0.23 1.59 4.65 0.53 0.39 0.68 27.87
S3 ID 0.89 9.01 4.79 18.94 0.49 1.16 1.32 2.01 5.08 1.66 0.71 2.76 48.82
ij 0.72 0.57 0.90 0.16 0.52 0.46 0.17 0.25 0.13 0.25 0.48 0.84 5.45
AS -0.80 0.80 -0.80 0.80 -0.80 0 0 0.80 0 -0.18 -0.62 0.00 -0.80
ET 1.69 6.02 5.59 3.76 1.29 1.16 1.32 0.28 0.71 1.84 1.33 2.76 27.75
W 0.72 2.76 0.90 14.54 0.52 0.46 0.17 1.18 4.50 0.25 0.48 0.84 27.32
^All values are reported in inches.
-------
Monthly soil moisture changes and monthly evapotranspiration used in
the analyses were computed using methods outlined by the EPA (Fenn et
al., 1975). These methods are described in Appendix G.
3.3.2.5 Water Quality
Ground-water samples were taken periodically for the analysis of
selected parameters (Table 3-10). Water samples were generally collected
in July 1984, September 1984, January 1985 and April 1985 along both
Transects SI and S3. Wells whose construction had not been completed
when the July sampling was done were generally sampled in early August.
The August water samples from well S3C3 were broken during shipment, so
no analyses are available for this well at that time. Also, wells S3B1
and S3B5 were sampled only in January 1985.
As discussed for the previous study areas, water samples were
collected in the Surf City study area with two objectives in mind. One
objective was to define the relationship between saltwater and freshwater
in the shallow aquifer. The second objective was to define the current
impact of wastewater disposal on the quality of water in the shallow
aquifer.
3.2.2.5.1 Relationship Between Freshwater and Saltwater
Measured chemical properties of the ground water used to aid in
defining saltwater intrusion into the shallow aquifer included sodium
concentration, chloride concentration, total dissolved solids con-
centration and specific conductance. Sodium and chloride are the major
constituents in saltwater. Total dissolved solids measures all solids in
solution in the water, including sodium and chloride. Specific conduc-
tance measures the ability of water to conduct an electrical current, and
generally increases with an increase in total dissolved solids content in
the water.
Elevated total dissolved solids concentrations had a strong correla-
tion with elevated sodium and chloride concentrations in water from the
shallow aquifer along both transects in Surf City, and is a good indica-
tor of saltwater intrusion into the aquifer. The total dissolved solids
content in the water was used to determine the presence of saltwater and
freshwater in the shallow aquifer.
Elevated specific conductance also correlated well with increased
sodium and chloride concentrations in water from the aquifer.
Variations in the total dissolved solids content of water in the
shallow aquifer at Surf City are apparent. Freshwater exists at the sur-
face of the shallow aquifer at all well sites except site S1A, where
brackish water was encountered. The effects of saltwater intrusion into
the aquifer increase the total dissolved solids content of the water to
saline levels below the depth of the shallowest monitoring wells along
Transect SI. Along Transect S3, the total dissolved solids content of
the water increases to brackish levels below the depth of the shallowest
monitoring wells. Definitions for fresh, brackish and saline waters are
given in Section 3.1.2.5.1. The variation in total dissolved solids con-
tent along Transect S3 is shown in Figure 3-37.
3-73
-------
TABLE 3-10
SUMMARY OF GROUND-WATER QUALITY ANALYSES FOR SURF CITY(1)
Nitrate
Fecal
Total
Ammo-
plus
coliforn
dis-
nia
nitrite
Alkalin-
Hardness
Ortho-
Temper-
Specific
(colonies
fell
Sampling
Chlo-
solved
(mg/l
(•g/1
ity {mg/l
(¦g/1 as
NBAS
phosphate
ature
conductance
P«
per 100/
ID
date
Sodi.ua
ride
solids
as N)
as N)
as CaCOi)
CaCO,)
(¦a/1)
(¦a/1 as P)
*C
(unhos/cm)
(s.u.)
ml)
Surf City
Transect S1
S1A1
193ul84
790
1450
3186
0.02
1.13
143
760
0.04
0.18
22
5300
7.86
<1
160ct84
266
493
1302
0.85
3.65
177
320
0.07
0.10
23
1550
7.72
<1
21Jan85
5 500
3381
7118
0.316
3.75
171
1000
<0.02
0.24
14
6200
7.73
2
12Apr85
8590
1579
3602
0.73
3.66
159
758
0.03
0.13
16
3860
7.85
<1
S1A2
193ul84
6600
17150
32970
0.10
0.16
96
5733
0.03
1.54
21
40500
7.64
<1
160ct84
8683
19131
23480
0.91
0.36
139
5520
<0.02
0.27
18
39000
7.45
<1
213an85
7320
15226
40474
1.69
<0.05
131
5750
<0.02
0.38
-
34500
8.00
<1
12Apr85
7510
12872
32747
5.98
0.43
125
5189
<0.02
0.09
18
25700
7.68
<1
S1A3
2Aug84
9000
18700
34048
0.02
<0.05
104
5600
<0.02
0.07
23
47243
7.50
<1
160ct84
9290
17700
34740
0.87
<0.05
135
5800
<0.02
0.03
19
41500
7.38
<1
213an85
7460
15693
37246
1.51
<0.05
130
5900
0.03
0.10
-
37000
7.62
54
12Apr85
7560
15842
37283
3.26
0.08
123
5320
<0.02
0.06
18
27500
7.47
<1
S1B1
193ul84
13
31
542
0.11
0.24
135
250
0.05
0.12
25
481
7.83
<1
160ct84
14
26
404
<0.01
0.61
173
220
0.15
0.02
23
340
7.47
<1
213an85
69
33
250
0.19
0.50
171
200
<0.02
0.13
14
315
7.97
<1
12Apr85
850
29
246
0.12
0.42
159
197
<0.02
0.08
16
600
6.18
<1
S1B2
193ul84
8700
16750
37096
0.45
<0.05
122
5800
0.03
0.38
22
41000
7.61
<1
160ct84
8467
16497
34872
0.82
<0.05
137
5200
0.04
0.13
20
39000
7.47
<1
213an85
7840
14385
32344
1.55
<0.05
142
5700
<0.02
0.25
_
29000
7.66
2
12Apr85
7440
15039
32703
3.38
<0.05
134
5207
<0.02
0.13
19
39500
7.62
<1
S1B3
2Aug84
9700
18900
36640
0.73
<0.05
143
5880
<0.02
0.19
22
51075
7.25
<1
160ct84
9574
16538
38788
1.04
<0.05
142
5650
0.06
0.03
22
44000
7.25
2
213an85
8690
16347
35698
2.41
<0.05
146
6250
<0.02
0.50
-
40000
7.49
1
12Apr85
8440
17000
37131
2.64
<0.05
137
5771
<0.02
0.04
19
42300
7.51
<1
-------
TABLE 3-10
(continued)
SUMMARY OF GROUND-WATER QUALITY ANALYSES FOR SURF CITY
Well
ID
Sampling
date Sodium
Chlo-
ride
Total
dis- nia
solved (mg/1
solids as N)
Nitrate
plus
nitrite
(»g/l
as N)
Alkalin-
ity (mg/1
as CaCO^)
Hardness
(Mg/1 as
CaCQvt)
~CAS
(mq/1)
Ortho-
phosphate
(mq/1 as P)
Temper-
ature
*C
Specific
conductance
(l»hos/cw)
PH
(s.u.)
Fecal
coliforni
(colonies
per 100/
ml)
Surf City (cont'd)
Transect S3
S3A1
193ul84
16
36
528
0.19
0.96
135
160ct84
49
103
698
<0.01
<0.05
208
210an85
121
64
602
0.09
4.15
193
S3A2
12Apr85
850
196
789
0.27
2.78
146
193ul84
3080
6500
12874
0.16
<0.05
178
160ct84
2601
4666
9924
0.37
<0.05
234
213an85
2210
4203
9700
0.84
<0.05
228
12Apr85
2280
3829
8643
0.67
<0.05
212
S3A3
Mug 84
7400
15300
30108
0.05
<0.05
148
160ct84
7375
13894
34924
0.97
<0.05
250
213an85
5980
11956
27222
3.17
<0.05
175
12Apr85
5950
12890
28795
2.25
1.60
146
S3B1
213an85
72
14
206
0.07
<0.05
154
S3B2
193ul84
710
1400
3312
0.12
<0.05
204
160ct84
830
1669
4020
0.17
<0.05
225
213an85
970
1495
3444
0.57
<0.05
230
12Apr85
1200
1171
3130
1.25
1.44
239
S3B3
193ul84
6100
11750
22252
0.39
<0.05
165
160ct84
6229
10980
24436
0.17
<0.05
340
213an85
5870
9621
20802
1.73
<0.05
203
12Apr85
5750
10555
22605
2.75
0.72
182
S384
193ul84
11000
21300
39590
0.61
<0.05
256
160ct84
10395
20168
52648
<0.01
<0.05
347
213an85
15810
16207
37218
3.14
<0.05
324
12Apr85
8590
18869
40798
7.60
0.77
310
S3B5
213an85
160
78
438
0.34
<0.05
218
S3C1
193ul84
8
10
682
0.56
0.45
200
160ct84
9
15
268
0.16
<0.05
198
213an85
82
93
22S
0.42
<0.05
166
12Apr85
560
63
643
0.45
<0.05
205
S3C2
193ul84
1830
3650
7688
0.47
0.07
209
160ct84
2300
3826
8580
<0.01
<0.05
225
213an85
2190
3363
7586
1.23
<0.05
228
12Apr85
1350
3940
7992
2.93
0.62
216
S3C3
160ct84
9487
16788
37122
0.16
<0.05
413
213an85
8170
17655
35654
3.46
<0.05
448
12Apr85
8390
19408
42633
4.57
0.06
430
258
420
445
357
2500
1900
2050
1466
5500
4840
4875
4568
158
1040
860
900
752
3300
3940
4550
3760
5900
7020
6900
6519
250
260
270
250
237
2000
1470
1400
1407
5980
6425
6278
<0.02
<0.02
<0.02
<0.02
<0.02
0.03
<0.02
<0.02
<0.02
<0.02
0.08
<0.02
<0.02
<0.02
<0.02
<0.02
0.02
<0.02
<0.02
<0.02
0.04
<0.02
<0.02
<0.02
0.03
<0.02
0.04
<0.02
<0.02
0.02
0.05
<0.02
<0.02
<0.02
<0.02
<0.02
<0.02
0.06
0.03
4.20
0.04
1.05
0.62
0.05
0.38
1.84
0.31
0.19
0.37
0.04
0.32
0.14
0.20
0.18
0.32
0.84
1.43
0.36
0.34
0.16
0.08
0.22
0.07
0.14
0.04
0.08
0.23
0.28
0.23
0.13
0.32
1.41
0.15
0.24
22
403
7.31
2
21
970
7.27
<1
14
610
7.67
<1
16
1050
7.48
<1
22
15000
7.48
<1
18
25800
7.17
<1
-
17400
7.65
<1
18
12100
7.67
<1
22
40755
7.08
>4600
18
34000
7.10
<1
-
29900
7.38
<1
18
32800
7.33
1
19
345
8.18
<1
23
3850
7.55
<1
19
6800
7.34
<1
-
8500
7.57
2
18
4550
7.59
<1
23
26500
7.33
<1
19
28700
7.15
<1
-
25900
7.47
<1
18
25800
7.44
<1
23
43000
6.93
<1
19
47700
6.93
2
-
41000
7.19
<1
18
35500
7.35
<1
18
4700
7.94
<1
22
435
7.35
<1
19
480
7.45
<1
13
305
7.94
<1
15
590
7.89
<1
22
9800
7.64
<1
19
14000
7.52
<1
13
10000
7.67
<1
18
10100
7.76
<1
19
40500
7.02
<1
-
35200
7.00
<1
17
43500
7.05
<1
^All analyses are in milligrams
per liter (mg/1)
unless otherwise noted.
-------
40'
2o:
SEA LEVEL.
-20'.
-40'.
-60'.
-80'.
-100'.
-120'.
o>
E
z
o
I-
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-------
3.3.2.5.2 Effects of Wastewater Disposal
Measured chemical properties of the ground water used to aid in
defining the effects of wastewater disposal to the shallow aquifer
included nitrate plus nitrite concentration (nitrate/nitrite), ammonia
concentration, orthophosphate concentration, methylene blue active
substances (MBAS) concentration, and fecal coliform concentration.
Nitrate, nitrite, ammonia and orthophosphate are common nutrients present
in wastewater. MBAS are substances used in detergents and do not occur
naturally in the environment. Fecal coliform are a group of bacteria
which come from the intestines of mammals and may be found in wastewater
and sometimes in storm water runoff.
Nitrate/nitrite and ammonia, reported in mg/1 as nitrogen (N), were
detected in ground water along both transects in Surf City (Table 3-10).
Variations in nitrate/nitrite and ammonia concentrations along Transect
S3 are shown in Figures 3-38 and 3-39, respectively. Although data is
sporadic, a trend toward decreasing nitrate/nitrite concentrations with
depth is indicated for Transect S3. The same trend is more apparent upon
examination of the data for Transect SI. The highest nitrate/nitrite
concentrations of the study were detected from Surf City wells, with con-
centrations generally greater than 3 mg/1 at well S1A1 and concentrations
as high as 4.15 mg/1 at well S3A1. Ammonia concentrations showed a defi-
nite trend to increase with depth along both Surf City transects.
Nitrate, nitrite and ammonia are contaminants which are commonly
found in ground water. The presence of these constituents in the shallow
ground water could, therefore, be indicative of the impact of wastewater
disposal. The drinking water standard for nitrates is 10 mg/1 as nitro-
gen (N). There are no drinking water standards for ammonia.
Orthophosphates, reported in my/1 as phosphorus (P), were also
detected in ground water along both transects. Variations in
orthophosphate concentrations along Transect S3 are shown in Figure 3-40.
Orthophosphate concentrations along Transect S3 appear to increase with
depth, with the exceptions of well S3B4, which shows a definite decrease,
and the January reading from well S3A1, which is among the highest of the
study.
The presence of phosphorous compounds in the ground water is typi-
cally a result of wastewater disposal. The usual sources for phosphorous
are organic waste products and phosphate detergent residues. The highest
observed level of orthophosphate was 4.20 mg/1. There are no drinking
water standards for orthophosphates.
Only minor concentrations of MBAS were detected in ground-water
samples from monitoring wells at Surf City. The highest MBAS level
detected was 0.15 mg/1 at well S1B1. The recommended secondary drinking
water standard for MBAS is 0.50 mg/1. The source of MBAS 1n wastewater
is synthetic foaming agents present in modern detergents. Variations in
MBAS concentration detected along Transect S3 are shown in Figure 3-41.
3-77
-------
40'.,
20!
SEA LEVEL.
-20'.
-40'.
-60'.
-80'.
-100'-
-120'J
INTRACOASTAl
WATERWAY
Shallow
sand aquifer
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EXPLANATION
% Generalized water table
-J Well site showing location
I of sampling intervals
¦Jgl Nitrate/Nitrite concentration.
Kj Number in parenthesis
«j| represents observed
concentration when the
vertical scale is exceeded
* Nitrate/Nitrite not detected
in analysis
Figure 3-38. Variation in nitrate plus nitrite
Transect S3.
concentration along
3-78
-------
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EXPLANATION
2 Generalized water table
Well site showing location
of sampling intervals
Ammonia concentration.
Number 1n parenthesis
represents observed
concentration when the
vertical scale is
exceeded
* Arrmonia not detected
In analysis
Figure 3-39. Variation in ammonia concentration along Transect S3.
3-79
-------
4o;
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SEA LEVEL.
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S Generalized water table
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o| Orthophosphate concentration. Number
*7| In parenthesis represents observed
31 concentration when the vertical
scale is exceeded
Figure 3-40. Variation in orthophosphate concentration along Transect S3.
3-80
-------
40'-
20'
SEA LEVEL.
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EXPLANATION
^ Generalized water table
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# MBAS not detected in
analysis
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LSEA LEVEL
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Figure 3-41. Variation in MBAS concentration along Transect S3.
3-81
-------
Fecal conform were found in 10 of the 61 ground-water samples
collected in Surf City. The fecal coliform count in eight of the
samples, however, was either one or two col/100 ml. One of the two high
concentrations occurred in August 1984 in well S3A3 and was greater than
4,600 col/100 ml. The other high value occurred in January 1985 in well
S1A3 and was 54 col/100 ml. The significance of high fecal coliform con-
centrations in these deep wells without intermediate values in shallower
adjacent wells 1s not known.
Alkalinity and hardness of the ground water were measured as overall
indicators of water quality. Alkalinity Is a measure of the carbonate
and bicarbonate 1ons in the water, with maximum levels of approximately
400 mg/1 as calcium carbonate (CaC03) considered to represent no health
problem. Hardness 1s a measure of the amount of calcium, magnesium and
Iron 1n the water. A strong relationship between these parameters and
saltwater intrusion Into the aquifer was observed from the data (Table
3-10).
Alkalinity 1n water from the shallow aquifer was fairly uniform
(Table 3-10). The alkalinity of the water ranged from 135 to 200 mg/1 as
CACO3 at the water-table surface and from 96 to 218 mg/1 as CaC03 at the
base of the aquifer. The alkalinity of the water 1s 1n the range of that
generally found in ground waters.
The hardness of the water increased significantly with depth 1n the
aquifer (Table 3-10). The hardness of the water at the water-table sur-
face ranged from 158 to 760 mg/1 as CaC03. At the base of the aquifer,
the hardness ranged from 2000 to 5800 mg/1 as CaC03. The high hardness
at the aquifer base reflects saltwater intrusion Into the aquifer 1n that
area. Water is generally considered to be hard water when the hardness
exceeds 150 my/1, and very hard vrtien in excess of 300 mg/1 as CaC03.
Since hardness in water can be easily removed with treatment, and because
hardness concentrations in water have not proven to be health-related, no
criterion exists for raw waters used for public water supply.
3.3.3 Summary of Hydroyeoloyic Setting for the Surf City Study Area
The hydrogeology at Surf City was studied to Identify the movement
of ground water in the shallow aquifer underlying Topsail Island, to
identify the components of recharge to the aquifer and their magnitude,
and to identify the existing quality of ground water underlying the
island. The results of this study can be summarized as follows:
Topsail Island is underlain by three aquifers.
The shallow sand aquifer, consisting of sand and shells,
extends downward from land surface to depths of 30 to 40 feet
and is separated from the deeper aquifers by sandy si It and
clay.
Ground-water movement 1n the shallow sand aquifer 1s variable
and is Influenced by tidal fluctuations and the presence of
saline water 1n the aquifer.
3-82
-------
Precipitation accounted for about 80 percent of the recharge
to the shallow sand aquifer and wastewater accounted for the
remainder.
Brackish to saline water occurs near the base of the shallow
sand aquifer and is also present throughout the aquifer in
the vicinity of well site S1A.
Disposal of wastewater Into the shallow aquifer has had a
minor impact on ground-water quality.
3-83
-------
4.0 PROBABLE HYDROLOGIC IMPACTS ASSOCIATED
WITH DEVELOPMENT ACTIVITIES
The probable impacts on ground-water levels and water quality of
continued development on the barrier islands were investigated. The data
collected during this study formed the basis for the investigation.
4.1 Ground-Water Levels
A simple analytical model for computing changes in ground-water
levels that might result from increased wastewater disposal to the
aquifer system underlying the islands was identified and tested. This
model was based on the physical characteristics of the islands and
underlying aquifer system.
4.1.1 Identification of Predictive Water-Level Model
The aquifer system underlying each of the barrier islands studied
consisted of an upper unconfined or semi confined aquifer that overlies
deeper confined aquifers. The upper aquifer is composed of sands and
shells and is separated from the lower aquifers by confining beds that
are composed of silt and clay. Water movement to the deeper aquifers is
restricted due to the presence of the confining beds. The confining beds
occur at depths varying from as little as 25 feet at Atlantic Beach to as
much as 100 feet at Kill Devil Hills.
Ground-water movement in the upper, or shallow, aquifers is
generally away from the central part of the islands toward discharge
points in the ocean and sound. Flowpaths along cross-sections perpen-
dicular to the islands are similar in this case.
The shallow aquifer in each study area can be represented approxi-
mately as an aquifer of infinite length and narrow width that is composed
of permeable sands and shells. The upper boundary of this model aquifer
consists of a water table that is free to move vertically. Its lower
boundary consists of relatively impermeable confining beds. The model
aquifer is in hydraulic communication with constant head boundaries along
each side throughout its length. A schematic representation of this
model aquifer is presented in Figure 4-1.
Water movement through the model aquifer occurs laterally, with
movement being from the center of the aquifer toward the constant head
boundaries. Water discharges from the aquifer at the interface with
these boundaries.
The equation for describing the average position of the water table
in the model aquifer is:
W(a2 - x2) + b2
H2 = J (3)
where: H = thickness of the water table aquifer, in feet;
4-1
-------
f
Sound
Barrier Island
Ocean A<
a. Plan view of model aquifer.
t>. Cross-section through model aquifer.
EXPLANATION
Generalized water table
Generalized ground-water flowpath
Figure 4-1. Simplified model for the shallow aquifer.
-------
W = net recharge to the water table, in feet per day;
K = hydraulic conductivity of the aquifer, in feet per
day;
a = half-width of the island, in feet;
b = depth below mean sea level to the top of the confining
beds, in feet; and
x = distance from the center of the island to the point at
which the water table elevation is required, in feet.
This equation is derived from the more general equation for finding the
elevation of the water table at any point between two constant head
boundaries of differing elevations (Fetter, 1980).
The water-table elevation is related to the aquifer thickness (H)
and depth below land surface to the confining beds (b) by the equation:
h = H - b (4)
where: h = height above mean sea level to the water-table sur-
face, in feet.
The variables a, x, b and h for the model aquifer are depicted in Figure
4-1.
Equation (3) is applicable to shallow aquifers on the barrier
islands when flow in the aquifer is predominantly horizontal, there is no
intrusion of saline water into the aquifer under the island and tidal
fluctuations have little or no effect on water levels. These conditions
are met reasonably well in the shallow aquifers in Kill Devil Hills and
Pine Knoll Shores and are probably met in the shallow aquifer in Atlantic
Beach.
Equation (3) cannot be applied to the shallow aquifer in Surf City.
Ground water of variable density underlies freshwater at very shallow
depths in the aquifer. Also, tidal fluctuations have a strong effect on
water levels in this study area. These conditions violate the assump-
tions used to derive the model equation.
4.1.2 Model Calibration
Measured average water-table elevations and those computed for each
transect using equation (3) did not agree using parametric values deter-
mined as a part of this study. For all transects except P2 in Pine Knoll
Shores, the computed elevations were substantially lower than those which
were measured. The computed elevations along Transect P2 were higher
than measured elevations.
4-3
-------
An analysis of the variables in equation (3) indicated that the
hydraulic conductivities that should be used in this equation are
generally lower than those determined by aquifer pumping tests. Apparent
hydraulic conductivities for each transect therefore were computed by
solving the equation for hydraulic conductivities using the measured
water-table elevation data. The ratio of hydraulic conductivity from
aquifer pumping tests to apparent hydraulic conductivities for the tran-
sects varied from 0.7 to 5.0 (Table 4-1).
The differences between measured hydraulic conductivities and com-
puted apparent hydraulic conductivities probably reflects in large part
differences between horizontal and vertical values of hydraulic conduc-
tivity, or anisotropy, in the shallow aquifers. The aquifer pumping
tests measured horizontal hydraulic conductivity. The computed apparent
hydraulic conductivites include the integrated effects of variations in
horizontal and vertical hydraulic conductivities. Layering of the sands,
shells and silty sands noted in the shallow aquifers would be responsible
for this anisotropy. Ratios of horizontal to vertical hydraulic conduc-
tivities between 2 and 20 are commonly found in relatively clean sands
(Fetter, 1980).
Changes required in the other independent variables in equation (3)
to match water-table elevations at the center of the island may not be
justified. The net recharge required to reproduce the observed water-
table elevations at the island center was generally twice that which
reasonably could be expected on the barrier islands. The measured
aquifer thickness along the transects would generally need to be reduced
by 50 percent or more and the measured island half-width would yenerally
need to be increased by a factor of 1.5 to 2 in order to produce accep-
table results.
Average water-table elevations computed along transects for the
study period using equation (3) with the calibrated apparent hydraulic
conductivities were in fair agreement with observed elevations in the
center one-half of the transects (Table 4-2). The recharye values needed
for these computations were taken from the water balance analyses for the
transects. The aquifer thickness below sea level and island half-width
needed for the computations were determined from the hydrogeologic cross-
sections.
Observed water-table elevations are higher in areas near the ocean
and sound than those computed using equation (3). One reason for this
discrepancy is that no allotment was made for the subsea outflow face
that must exist for freshwater to discharge into either the ocean or the
sound. Anisotropy in the aquifer deposits, higher wastewater loadings in
the areas near the ocean and sound, and average elevations of the ocean
and sound greater than mean sea level would be other reasons for this
discrepancy.
An equation that accounts for the presence of the subsea outflow
face can be used to compute water-table elevations near the ocean and
sound (Fetter, 1980). This equation is
h
(5)
4-4
-------
TABLE 4-1
COMPARISON BETWEEN MEASURED AND APPARENT HYDRAULIC CONDUCTIVITIES
Transect
Measured
Apparent
K
ID
hydraulic
hydraulic
ka
conductivity
conductivity
(K,ft/day)
(Ka,ft/day)
K1
73
22.3
3.3
K2
73
27.6
2.6
K3
73
36.3
2.0
A1
63
12.5
5.0
A2
63
34.5
1.8
PI
63
24.0
2.6
P2
63
90.4
0.7
4-5
-------
TABLE 4-2
COMPUTED AND OBSERVED WATER-TABLE ELEVATIONS ALONG TRANSECTS
Transect Site Island Net Aquifer Distance
ID half- recharge . thickness from
width (ft/day)'*' below island
(feet) sea level center
(feet) (feet)
Computed
water-table* j)
elevation
(MSL)
Mean
water-table
elevation
(MSL)
Obeserved
range in
water-table
elevation
(MSL)
Kill Devil Hills
K1
K2
K3
C
B
D
A
E
C
D
B
A
E
D
C
E
B
F
A
G
2060
2460
3900
.00416 55
.00431 75
.00403 75
0
625
800
1625
1875
250
975
1200
2125
2450
500
575
1575
1750
2450
3425
3550
6.2
5.7
5.4
2.4 (2.9)
1.1 (1.9)
6.0
5.1
4.7
1.6 (2.5)
0 (0.4)
10.4
10.4
8.9
8.5
6.5
2.5 (3.2)
1.9 (2.8)
6.2
6.0
5.1
4.2
3.1
6.0
6.9
5.0
3.7
2.0
10.4
9.6
8.4
6.8
6.2
3.7
2.0
5.6-7.3
5.5-7.1
4.5-6.3
3.0-7.1
2.2-3.4
5.5-7.2
6.1-8.2
4.3-5.8
2.4-5.8
1.6-2.4
10.1-11.6
9.1-10.8
7.2-9.6
6.3-7.9
5.9-6.8
2.9-5.3
1.8-2.1
Atlantic Beach
At B 655
C
A
D
A2 B 900
C
A
Pine Knoll Shores
.00873
.00863
35
22
150
225
525
525
125
505
690
3.8
3.6
1.5 (1.7)
1.5 (1.7)
4.1
3.0
1.8
4.2
3.9
3.2
2.4
4.2
2.6
3.2
3.3-6.7
3.0-6.0
2.7-4.7
1.6-3.6
3.4-6.5
1.9-3.4
2.6-4.7
PI
P2
C
D
B
E
A
C
D
B
E
A
1465
1960
.00637
.00688
50
40
62
490
650
1090
1250
335
850
1275
1810
1860
5.3
4.8
4.4
2.5 (2.7)
1.5 (2.0)
3.4
2.9
2.0
0.5 (1.1)
0.4 (0.9)
5.4
4.8
5.1
3.6
4.3
3.5
2.6
4.0
2.5
3.2
4.3-7.4
3.8-7.0
4.2-5.9
3.1-5.3
3.5-5.3
2.7-4.8
2.3-3.7
3.4-5.5
1.8-3.3
2.3-4.2
(1)
(2)
Number in parenthesis is the water table elevation computed using equation (5).
Net recharge is based on Dune 1984 to February 1985 data for Kill Devil Hills, 3une 1984 to April 1985 data
for Atlantic Beach and 3une 1984 to March 1985 data for Pine Knoll Shores.
4-6
-------
where: x' = distance inland from the shoreline, in feet;
q » discharge per unit length of shoreline, in cubic feet
per day per foot; and
K ¦ apparent hydraulic conductivity, in feet per day.
The discharge per unit length of shoreline is related to net recharge by
the equation
q = Wa (6)
where W and a have been defined earlier. Equation (5) is valid to a
distance inland from the shoreline of about 0.25a.
The water-table elevations near the ocean and sound computed using
equation (5) are in closer agreement to observed results than those com-
puted using equation (3)(Table 4-2). The observed water-table eleva-
tions, however, are still generally higher than the computed elevations.
The remaining discrepancy between measured and computed water-table ele-
vations probably results from one or more of the additional reasons
stated earlier.
4.1.3 Model Use for Estimating Changes in Ground-Water Levels
The impacts of wastewater disposal during the study period on water
levels along transects were investigated using equation (3). Computed
water-table elevations resulting from precipitation were compared with
computed water-table elevations resulting from precipitation plus
recharge by wastewater disposal (Table 4-3).
The increase in water-table elevations resulting from wastewater
disposal during the study period was greater at Atlantic Beach than at
either Kill Devil Hills or Pine Knoll Shores. Intuitively, this is
expected, as the largest wastewater loading to the aquifer system is
occurring at Atlantic Beach. The water-table elevation is approximately
one foot higher at the center of Bogue Banks in Atlantic Beach than that
which would occur if there was no wastewater disposal on the island. The
water-table elevations at Kill Devil Hills and Pine Knoll Shores are
about 0.6 feet and 0.1 to 0.4 feet higher, respectively, than those that
would occur without the addition of wastewater.
The impact of equal volumes of wastewater disposal on changes in
average water levels, however, was greatest at Kill Devil Hills. That
is, rises in water levels per unit volume of wastewater disposal at tran-
sects in Kill Devil Hills were greater than those which occurred at tran-
sects in the other study areas. A closer examination of equation (3)
Indicates that water-table elevations are relatively sensitive to island
width and depth to confining beds. The greater the combination of island
width and depth to confining beds (within the range of widths and depths
Investigated in this study), the greater the impact of incremental values
of recharge on changes 1n water levels.
4-7
-------
TABLE 4-3
COMPUTED AVERAGE WATER-TABLE ELEVATIONS AT CENTER OF TRANSECTS
WITH AND WITHOUT WASTEWATER DISPOSAL
Transect
ID
Recharge by
rainfall
(ft/day)
Water-table
elevation
resulting
from
rainfall
disposal
(MSL)
Recharge
by
rainfall
pi us
wastewater
disposal
(ft/day)
Water-table
elevation
resulting
from
rainfall
plus
wastewater
disposal
(MSL)
Kill Devil Hills
K1
.00377
5.7
.00416
6.3
K2
.00377
5.3
.00431
6.0
K3
.00377
9.9
.00403
10.5
Atlantic Beach
A1
.00625
2.9
.00873
4.0
A2
.00625
3.1
.00863
4.2
Pine Knoll Shores
PI
.00625
5.3
.00637
5.4
P2
.00625
3.1
.00688
3.5
Surf City
SI
.00600
1.6
.00735
2.0
S3
.00600
1.7
.00713
2.0
4-8
-------
Wastewater disposal at Surf City may be causing ground-water levels
there to be 0.3 to 0.4 feet higher than those that would occur naturally
(Table 4-2). This estimate is based on using equation (3), which,
although not strictly applicable to hydrologic conditions at Surf City,
does provide a means for obtaining rough estimates.
The data used for the above computations are essentially the same as
that data used earlier for computing average water-table elevations along
transects. However, for computing water-table elevations resulting from
precipitation, wastewater recharge along each transect was subtracted
from total recharge along the transect.
Equation (3) estimates the average impact of wastewater disposal on
water-table elevations and assumes that steady-state conditions prevail
in the aquifer. These limitations restrict the usefulness of this
equation. The impact of changes in wastewater disposal volumes over
short time periods, such as one season of the year, cannot accurately be
taken into account.
The utility of equation (3) to planning for wastewater management
lies in its ability to estimate the cumulative impacts of development on
ground-water levels. The equation could be used to compute the maximum
probable impact that various incremental increases in wastewater disposal
would have on observed average water-table elevations.
4.1.4 Model Use for Planning Purposes
Suppose that long-range development plans in an area call for a
maximum population growth such that the increased average water use
across the island will amount to an additional wastewater disposal rate
to the shallow aquifer of 10.0 inches per year. The problem is to deter-
mine the probable impact of this added wastewater disposal on water
levels in the shallow aquifer.
The first step in determining the probable impact on water levels is
to determine the depth below mean sea level of the confining beds at the
island mid-point and within the area of interest. A boring could be
drilled for this purpose. In our case, let us assume the depth below
land surface to the confining beds is found to be 60.0 feet and that the
land surface elevation 1s 10.0 feet. The depth below mean sea level to
the confining beds would then be 50.0 feet.
The next step is to determine the elevation of the water table at
the island mid-point. To accomplish this, the boring drilled to deter-
mine the depth to confining beds can be backfilled to a point about 10
feet below the water table and completed as a shallow monitoring well.
The depth to water in this well, measured from a reference point on the
well that has been surveyed and has a known elevation, can be used to
determine the water-table elevation 1n the area. Let us assume that the
water-table elevation determined in this manner is 4.00 feet.
4-9
-------
The third step is to determine the half-width of the island. This
information can be taken from any acceptable base map for the area. For
our example, let us assume that the island half-width is 1,500 feet.
The fourth step is to estimate current yearly net recharge to the
shallow aquifer in the proposed development area. Current yearly net
recharge includes recharge from precipitation and wastewater disposal. A
good estimate for long-term yearly recharge from precipitation is 20.0
inches per year based on work done by Wilder (1978) in northeast North
Carolina and work done by Winner on the barrier islands. Current
wastewater disposal can be assumed to be equal to water use and can be
determined from water use records. Yearly net recharge will be 21.0
inches, assuming for our example that wastewater disposal is equivalent
to one inch.
The information needed to determine the impact on water levels of
the added wastewater disposal is now available. The apparent hydraulic
conductivity is computed from equation (3) and found to be 25.9 ft/day.
The estimated current water-table elevations across the island are now
computed using equation (3), the apparent hydraulic conductivity and
current yearly net recharge. The computational process is then repeated
after adding the additional wastewater disposal to the yearly net
recharge. The difference between water-table elevations computed with
and without the added wastewater disposal is the impact on water levels
for the proposed development. A summary of the computations is presented
in Table 4-4. A flow diagram showing the computational process is pre-
sented in Figure 4-2.
4.1.5 Water-Table Fluctuations Due to Short-Term Precipitation Events
Caution must be exercised when using equation (3) to assess the
impacts of wastewater disposal. In our example, the estimated increase
in water levels due to the increased wastewater disposal will be approxi-
mately two feet at the center of the island. The water table was six
feet below land surface at this point when the monitoring well was
drilled, suggesting that a two-foot rise would not cause the ground-water
table to surface. However, water-table fluctuations of two or three feet
caused by precipitation were observed on the barrier islands during the
course of this study. These fluctuations need to be considered in any
detailed analysis involving assessment of the probability of ground-water
levels surfacing due to increased water-table elevations caused by
wastewater disposal.
The probability for a given rise in the water table is directly
related to the probability of various rainfall events. Estimated short-
term rises in the ground-water table for 24-hour rainfall events with
recurrence intervals of 5, 10, 25, 50 and 100 years are tabulated in
Table 4-5. The water-table rise was computed by dividing rainfall by
aquifer porosity and is only applicable to that point where the water
table surfaces.
4-10
-------
TABLE 4-4
IMPACTS ON WATER LEVELS OF PROPOSED DEVELOPMENT FOR
HYPOTHETICAL CASE
Distance from
island center
(feet)
Computed existing
water-tab!e
thickness
(feet)
Computed water-
table thickness
after develop-
ment
(feet)
Increase in
water-tabl e
level
(feet)
0
54.0
55.8
1.8
300
53.8
55.6
1.8
600
53.4
54.9
1.5
900
52.6
53.8
1.2
1,200
51.5
52.2
0.7
4-11
-------
Compute apparent hydraulic
conductivity (k) by
K = Wa2
(H2-b2)
Compute water-table
elevations (H) at
various distances (x)
from the island center by
H = ) +b 2)h
0 < X % .75a
(z,)
Figure 4-2. Flow chart for computing water-table elevations.
-------
Water-table rises greater than about four feet under current con-
ditions in any of the study areas may cause surface flooding by ground
water. Ground-water levels are generally at a depth of four feet or less
below ground surface. Thus, ground-water flooding due to 24-hour rain-
fall events can be expected to occur with a recurrence interval between
50 and 100 years in Kill Devil Hills and Atlantic Beach/Pine Knoll Shores
and with a recurrence interval between 10 and 25 years in Surf City
(Table 4-5).
Increased population growth on the islands will increase the fre-
quency of ground-water flooding. In the example given in Section 4.1.4,
the 10 inches of wastewater disposal resulting from our hypothetical
development will result in a 1.8-foot rise in average ground-water
levels. This rise, added to rises in water levels that can be expected
for the 5-year, 24-hour rainfall events, exceeds four feet in each study
area. Thus, ground-water flooding will occur with some regularity in the
vicinity of the hypothetical development, regardless of where on the
islands this development might occur.
Although the water table rises rapidly in response to precipitation,
the reverse is not true. The water table will recede quickly for one or
two days after a major rainfall event and then slow to a relatively uni-
form recession rate. The impact on water levels of a major rainfall
event, such as that which occurred in all three study areas in September
1984, will be noticeable for several weeks (see Figures 3-6, 3-19 and
3-36).
4.1.6 Alternate Approach for Model Calibration
An alternate approach for calibrating equation (3) to field con-
ditions that may be justified involves determining an apparent hydraulic
conductivity and apparent island half-width that, together, would repro-
duce the observed water-table elevations. This approach requires that
the water-table elevation be known at two or more points along a line
that extends across the width of the barrier island. A solution to
equation (3) is found by trial and error such that the measured and com-
puted water-table elevations are in approximate agreement. A comparison
between apparent and computed values of hydraulic conductivity and island
half-width using this alternate approach is presented in Table 4-6.
The apparent hydraulic conductivities computed using this alternate
approach generally are lower than those determined by aquifer pumping
tests, but are also generally in closer agreement to the measured values
than the apparent hydraulic conductivities computed earlier (Table 4-1).
Apparent hydraulic conductivity values lower than measured values are
expected due to the effects of anisotropy (Section 4.1.2).
The apparent island half-width along each transect is greater than
the measured island half-width. This is excepted. The anisotropy asso-
ciated with the sand deposits, coupled with the very gently sloping
shorelines on both the sound and ocean sides of the islands, suggests
that freshwater discharge could be occurring some distance beyond these
shorelines. The position of the subsea outflow face that defines where
freshwater discharge occurs to the sound and ocean should actually be
used to define the island half-width.
4-13
-------
TABLE 4-5
WATER-TABLE RISE ASSOCIATED WITH VARIOUS RAINFALL INTENSITIES
Location
Recurrence
i nterval
(years)
24-hour
rainfall^ '
(inches)
Water table
rise
(feet)
Remarks
Kill Devil Hills
5
6.0
2.6
10
7.0
3.1
25
8.0
3.5
50
9.0
3.9
100
10.0
4.4
Probable
surface
floodi ng
Atlantic Beach/
5
6.0
2.5
Pine Knoll Shores
10
7.0
2.9
25
8.5
3.5
50
9.0
3.8
100
10.5
4.4
Probable
surface
flooding
Surf City
5
6.0
3.1
10
7.0
3.6
25
8.0
4.2
Probable
surface
flooding
50
9.0
4.7
Probable
surface
flooding
100
10.0
5.2
Probable
surface
fl ooding
(^From Barfield et al. (1983).
-------
TABLE 4-6
COMPARISON BETWEEN MEASURED AND APPARENT HYDRAULIC
CONDUCTIVITIES AND ISLAND HALF-WIDTHS
Transect
ID
Measured
hydraulic
conductivity
(K,ft/day)
Apparent
hydraul1c
conductivity
(Ka.ft/day)
K
-*a
Measured
Island
half-width
(a.ft)
Apparent
Island
half-width
(aA.ft)
a
aA
K1
73
40
1.8
2060
2650
1.3
K2
73
45
1.6
2460
3150
1.3
K3
73
40
1.8
3900
4100
1.1
A1
63
25
2.5
655
950
1.5
A2
63
50
1.3
900
1080
1.2
PI
63
60
1.0
1465
2300
1.6
P2
63
300
0.2
1960
3500
1.8
4-15
-------
Average water-table elevations computed along transects for the
study period using equation (3) with calibrated apparent hydraulic con-
ductivities and island half-widths are generally in close agreement with
observed elevations (Table 4-7). The recharge values needed for these
computations were taken from the water balance analyses for the tran-
sects. The aquifer thickness below sea level needed for the computations
was determined from the hydrogeologic cross-sections.
The apparent hydraulic conductivities and island half-widths com-
puted for all transects except Transect P2 in Pine Knoll Shores appear
sensible. The reason for the wide discrepancy between apparent and
measured values for these parameters at that location is unknown.
4.1.7 Other Models
The work plan for this project (Applied Biology, Inc., 1984) iden-
tified three simple models that might be used for computing water-table
elevations. One of these models is that one described in this section.
Another model is one developed by Fetter (1972) that is based on the full
development of a freshwater lens surrounded by seawater beneath an
island. The third model was developed using the relationship between
changes in water-table elevations and changes in depth to water with a
dissolved solids content of 250 milligrams per liter observed by Winner
(1975) on the narrow islands that form the Cape Hatteras National
Seashore.
Fetter's model (Fetter, 1972) was not applicable for use in the
areas studied in this report. The shallow aquifer in each area was found
to be underlain by confining beds that preclude the full development of a
freshwater lens under the island.
The model developed based on Winner's observations was generally not
applicable for use in the areas studied in this report. This model is
based on assumptions similar to those used to develop Fetter's model.
More sophisticated ground-water models are available for computing
water-table elevations. These models can be categorized generally as
digital computer ground-water flow models. The use of digital computer
modeling techniques was beyond the scope of this project, although suf-
ficient data have probably been collected for constructing digital com-
puter ground-water flow models for each study area.
4.2 Ground-Water Quality
Ground-water quality data were collected along nine transects which
were selected in areas with differing levels of development. These tran-
sects were designated as high density, medium density and low density
development based on a visual impression of the degree of development
along each transect. The amount of wastewater disposal along each tran-
sect was also determined as a part of this study.
4-16
-------
TABLE 4-7
COMPUTED AND OBSERVED WATER-TABLE ELEVATIONS ALONG TRANSECTS
USING AN ALTERNATE APPROACH
Transect
Site
Net
Aquifer
Dlstance
Computed
Mean
Obeserved
ID
recharge
thickness
from
water-table
water-table
range In
(ft/day)
below
Island
elevation
elevation
water-tab le
sea level
center
(MSL)
(MSL)
elevation
(feet)
(feet)
(MSL)
Kll1 Devil
HII Is
K1
C
.00416
55
0
6.3
6.2
5.6-7.3
B
625
5.9
6.0
5.5-7.1
D
800
5.7
5.1
4.5-6.3
A
1625
4.0
4.2
3.0-7.1
E
1875
3.2
3.1
2.2-3.4
K2
C
.00431
75
250
6.0
6.0
5.5-7.2
D
975
5.5
6.9
6.1-8.2
B
1200
5.2
5.0
4.3-5.8
A
2125
3.4
3.7
2.4-5.8
E
2450
2.4
2.0
1.6-2.4
K3
D
.00403
75
500
10.1
10.4
10.1-11.6
C
575
10.0
9.6
9.1-10.8
E
1575
8.8
8.4
7.2-9.6
B
1750
8.4
6.8
6.3-7.9
F
2450
6.6
6.2
5.9-6.8
A
3425
3.1
3.7
2.9-5.3
G
3550
2.5
2.0
1.8-2.1
Atlantic Beach
A1
B
.00873
35
150
4.0
4.2
3.3-6.7
C
225
3.9
3.9
3.0-6.0
A
525
2.8
3.2
2.7-4.7
D
525
2.8
2.4
1.6-3.6
A2
B
.00863
22
125
4.1
4.2
3.4-6.5
C
505
3.3
2.6
1.9-3.4
A
690
2.6
3.2
2.6-4.7
Pine Knol1
Shores
PI
C
.00637
50
62
5.3
5.4
4.3-7.4
D
490
5.1
4.8
3.8-7.0
B
650
4.9
5.1
4.2-5.9
E
1090
4.2
3.6
3.1-5.3
A
1250
3.8
4.3
3.5-5.3
P2
C
.00688
40
335
3.3
3.5
2.7-4.8
D
850
3.2
2.6
2.3-3.7
B
1275
2.9
4.0
3.4-5.5
E
1810
2.5
2.5
1.8-3.3
A
1860
2.4
3.2
2.3-4.2
4-17
-------
Wastewater disposal, expressed in inches per month (in/month), is a
good measure of the relative potential impact of wastewater on ground-
water quality, assuming that long-term precipitation is roughly the same
for each transect location. Table 4-8 presents the mean ammonia,
nitrate/nitrite, MBAS and orthophosphate concentrations in ground water
for each transect. Also shown in this table is the average monthly
wastewater disposal for the study period. It can be seen that two of the
transects have substantially lower amounts of wastewater disposal than
the others. Transect K3 has wastewater disposal of 0.094 in/month and
Transect PI has 0.049 in/month. The two Atlantic Beach transects have
wastewater disposal of 0.869 and 0.905 in/month and are the transects
with the highest disposal rates. The remaining five transects have
disposal rates which fall between the two extremes.
4.2.1 Ammonia
The data in Table 4-8 suggest that no relationship exists between
the amount of wastewater disposal and the amount of ammonia found in the
ground water. Figure 4-3 includes a scatter diagram upon which the
wastewater disposal is plotted on the Y-axis and ammonia on the X-axis.
The greatest average ammonia, 2.14 mg/1, occurs along Transect K3, which
has a low wastewater disposal rate and low density of development. Pine
Knoll Shores Transect P2, a low density transect, also had high ammonia
even though the disposal rate was only moderate. In the Kill Devil Hills
area there appears to be an inverse relationship between density of deve-
lopment and ammonia concentration.
The range of ammonia values is from below detection limits to as
much as 17.2 mg/1 (well A2A4). Some of the higher ammonia values are in
brackish or saline water. If only wells with a total dissolved solids
content less than 1,000 mg/1 are considered, the maximum ammonia con-
centration is 10.70 my/1 (well P1C2).
In the wells where the ammonia content was in excess of 1.0 mg/1, it
can probably be assumed that there is some impact from man's activities.
Transects K3 and P2, both low density transects, and Transect A2, a high
density transect, have the greatest number of ground-water analyses with
an ammonia concentration greater than 1.0 mg/1. There are a number of
possible sources for ammonia, including septic systems, fertilizers and
animal wastes. It is not possible to pinpoint the source as wastewater,
especially as there was no obvious relationship between wastewater dispo-
sal rates and ammonia.
4.2.2 Nitrate/Nitrite
Nitrate plus nitrite (nitrate/nitrite) concentration in ground water
is yreatest in the Surf City area, although even there it is very low
(Table 4-8). There are no wells which exceed the maximum drinking water
level of 10 mg/1 as nitrogen for nitrate in drinking water. The greatest
nitrate/nitrite concentration was 4.15 mg/1, in well S3A1. Figure 4-3
includes a scatter diagram for nitrate/nitrite concentration as a func-
tion of the amount of wastewater disposal. There is no apparent pattern
to the relationship. Ninety-three percent of the analyses had
nitrate/nitrite levels of less than 1.0 mg/1, a level which generally
4-18
-------
TABLE 4-8
MEAN CONCENTRATIONS IN GROUND WATER OF SELECTED COMPOUNDS^
Transect
ID
Density
of
development
Wastewater
disposal rate
(in./month)
Ammonia
Nitrate/
nitrite
MBAS
Ortho-
phosphate
Kill Devil Hills
K1
Medium
0.141
0.70
0.33
0.024
0.27
K2
High
0.196
0.39
0.28
0.09
0.36
K3
Low
0.094
2.14
0.06
0.005
0.54
Atlantic Beach
A1
High
0.905
1.27
0.12
0.034
0.78
A2
High
0.869
2.09
0.19
0.076
0.18
Pine Knoll Shores
PI
Medium
0.049
0.97
0.005
0.44
0.81
P2
Low
0.253
2.04
0.03
0.02
1.55
Surf City
SI
Medium
0.493
1.24
0.62
0.022
0.22
S3
High
0.413
1.14
0.37
0.008
0.46
(^All values are reported in mg/1.
-------
1.°1
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£
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Ammonia concentration in mg/l as N
1.0
.9
8
•A1
* • A2
S1
S3*
•P2 k2
#K3 **K1
~PI
Sfi
1.0
.9
.8
.5
.4
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.2
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0 .1 .3 ¦» A * .6 .7 .9 .9 10 1.1 12 tS 14 15
Nitrata/nitrite concentration in mg/l as N
•
A1.
S1
CM
<
•
. s
.01 .02 A3 04 .06 .09 ,0> .08 .09 .1
MBAS concentration in
0 1'1 ^ A3 A'* .4%
mg/l
A2
•
s2
• A1
S3*
K2
K1. *
K3
P.1
Pl
V .1 .2 .$ A * .« J .8 .0 IjO 1.1 1.2 "S/» 1.6 1*
Orthophoaphate concentration in mg/l as P
EXPLANATION
Transect - S3 • Mean concentration of selected compound along transect
Figure 4-3. Comparison between wastewater disposal rate and mean
concentration in water of selected compounds.
4-20
-------
indicates no impact due to wastewater disposal. Only one well, S1A1, had
nitrate/nitrite above 1.0 my/1 every time that the well was sampled.
There is no apparent impact of wastewater disposal, or other activity, on
nitrate/nitrite levels other than at well S1A1.
4.2.3 NBAS
There is a maximum contaminant level for drinking water of 0.5 mg/1
MBAS, which is a measure of detergent in water. This standard was
exceeded in wells K2A1 (0.53 mg/1) and K2D1 (0.50 mg/1). In both cases
there were three other analyses at the well which were below the stand-
ard. Figure 4-3 includes a scatter diagram of MBAS concentration as a
function of the amount of wastewater recharge. There is no apparent
relationship between the two variables. No MBAS were detected in 48 per-
cent of the samples analyzed. In the remaining 52 percent of the
samples, MBAS were detected, but generally in very low amounts. The use-
fulness of the ground water has not been impaired by MBAS, except perhaps
at wells K2A1 and K2D1.
4.2.4 Orthophosphate
Orthophosphate is a soluble form of phosphorous which can come from
a number of sources, including wastewater. Phosphate in surface water is
a nutrient which can cause eutrophication if the waters are phosphate-
limited. There is no drinking water standard for phosphorous.
Figure 4-3 includes a scatter diagram which shows mean orthophos-
phate concentration along each transect as a function of wastewater
disposal. As with the other compounds, there does not appear to be any
relationship between the two variables. Only one quarter of the samples
exceed 0.50 mg/1 orthophosphate. The greatest orthophosphate value was
6.34 mg/1, in well P1D1. In the Pine Knoll Shores area, 13 of 36 analy-
ses exceeded 1.0 mg/1. The greatest mean value was 1.55 mg/1 along
Transect P2, a low density transect. Both of the Pine Knoll Shores tran-
sects had phosphate levels greater than either of the Atlantic Beach
transects, although the Atlantic Beach transects had much higher rates of
wastewater disposal and were both high density.
There does not appear to be any relationship between the occurrence
of ammonia and orthophosphate. Transect P2 had both relatively high
ammonia (2.04 my/1) and relatively high phosphate (1.55 my/1). Transect
A2 had relatively high ammonia (2.09 mg/1) but relatively low phosphate
(0.18 mg/1). The terms high and low are used here for comparison pur-
poses only and are not meant to imply high values in an absolute sense.
4.2.5 Fecal Coliform Bacteria
Fecal coliform bacteria were present in some of the samples from all
of the study areas. In Kill Devil Hills there were two samples with
coliforms. At Surf City 10 of 61 samples had coliforms. Six out of 36
analyses in Pine Knoll Hills had coliforms. Atlantic Beach had the
highest occurrence, with 33 of 90 samples showing coliforms. There is
evidence that some of these coliforms originated from surface flooding
during periods of heavy precipitation. This may have impacted up to 12
of the 33 samples which had coliforms.
4-21
-------
Coliform bacteria occur in areas of high, medium and low density of
development. However, there is a definite pattern, with the areas of
highest wastewater disposal, Al, A2, SI and S3, all having the highest
percentage of wells with coliforms present. As some of these wells were
impacted by flooding and not subsequently disinfected, the coliform data
should be interpreted with care. Some of the positive coliform tests may
have been caused by coliforms which were introduced into the ground water
by the flooded water.
4.2.6 Variation of Chemical Quality with Depth
At a number of locations well clusters were installed in order to
enable water samples to be withdrawn at various depths. One outcome of
this type of sampling is the ability to locate the saltwater interface
and zone of diffusion. The following parameters typically increase with
depth in the study areas and indicate the presence of brackish or salt
water: sodium, chloride, total dissolved solids and specific conduc-
tance. Hardness may also increase with depth 1f brackish and/or salty
water which may contain increased calcium and/or magnesium is encoun-
tered. Alkalinity appears to have no relationship with either depth or
salinity.
A detailed analysis has been made of the four water chemistry para-
meters (MBAS, ammonia, nitrate plus nitrite and orthophosphate) which
might be affected by waste water disposal. Mean values of each parameter
for each well in a cluster were computed. Some wells only had one
measurement and others had up to five. Well cluster S3B had two wells,
S3B1 and S3B5, with only one analysis, whereas the other three wells in
the cluster each had four analyses. In this case, only the wells with
four analyses were used.
The mean values for each cluster were compared and classified into
one of four categories:
1. Constant: Mean values varied by no more than 10 percent in each
well.
2. Decreasing: The uppermost well had the greatest value and was
at least 10 percent greater than any other value.
3. Increasing: The deepest well had the greatest value and was at
least 10 percent greater than any other value.
4. Variable: All other wells.
Table 4-9 illustrates results of this exercise.
Of the four parameters, only ammonia has a clear pattern; that of
increasing with depth (62 percent of the well clusters). MBAS and
nitrate plus nitrite decreased with depth in 38 percent of the wells,
which was more than any other pattern. Orthophosphate had a variable
pattern more than half of the time.
4-22
-------
TABLE 4-9
VARIATION OF CHEMICAL QUALITY WITH DEPTH
s-
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S-
C
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u
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Kill
Devil
Hills
Number
Percent
3
27
5
45
1
9
2
18
0 2 5
0 18 45
4 2 6 2 1
36 18 55 18 9
0 4 2 5
0 36 18 45
Atlantic Number
Beach
Percent
3 3 10
43 43 14 0
15 1114 1
14 72 14 14 14 58 14
114 1
14 14 58 14
Pine Number
Knoll
Shores Percent
12 2 10 0
17 33 33 17 0 0
4 2 5
67 33 83
0 1
0 17
0
0
0 1
0 17
0 5
0 83
Surf
City
Number 12 110
Percent 20 40 20 20 0
0 4 1
0 80 20
0 4
0 80
0 1
0 20
0 1
0 20
0 4
0 80
Total
Number
Percent
5 11 7603 18 88 11 73176 15
17 38 24 21 0 10 62 28 28 38 24 10 3 24 21 52
-------
Three of the four study areas had no particular pattern for all of
the parameters. However, at Atlantic Beach chemical concentrations
increased with depth in more than half of the wells for ammonia, nitrate
plus nitrite and orthophosphate. Atlantic Beach is also the area with
the greatest percentage of wastewater recharge.
There is no obvious explanation for the consistent pattern of
increasing ammonia concentrations with depth.
4-24
-------
5.0 REFERENCES
Applied Biology, Inc. 1984. Work plan for North Carolina barrier
islands ground-water study. Prepared for USEPA Region IV, NEPA
Compliance Section.
Barfield, B.J., R.C. Warner and C.T. Haan. 1983. Applied hydrology and
sedimentology for disturbed areas. University of Kentucky.
Fenn, Dennis G., Keith J. Hanley and Truett V. DeGeare. 1975. Use of
the water balance method for predicting leachate generation from
solid waste disposal sites. U.S. Environmental Protection Agency
Report 530/SW-168.
Ferris, J.G., D.B. Knowles, R.H. Brown and R.W. Stallman. 1962. Theory
of aquifer tests. U.S. Geol. Survey Water-Supply Paper 1536-E.
Fetter, C.W. Jr. 1972. Position of the saline water interface beneath
oceanic islands. Water Resources Research, Vol. 8, No. 5.
Fetter, C.W. Jr. 1974. Water quality and pollution - South Fork of Long
Island, New York. AWWA Water Resources Bulletin, Vol. 10, No. 4.
Fetter, C.W., Jr. 1980. Applied hydrogeology. Charles E. Merrill
Publishing Co., Columbus, OH.
Freeze, Allan R. and John A. Cherry. 1979. Groundwater. Prentice-Hall,
Inc., Enylewood Cliffs, NJ.
Israelsen, O.W., and V.E Hansen. 1962. Irrigation principles and
practices. John Wiley and Sons, Inc., New York, NY.
Layman, Leland L. 1965. Ground water exploration at Surf City, North
Carolina. North Carolina Department of Natural Resources
Ground-Water Circular No. 7.
LeGrand, Harry E. 1960. Geology and ground-water resources of the
Wilmington-New Bern area. North Carolina Department of Natural
Resources Ground-Water Bulletin No. 1.
Lohman, S.W. 1972. Ground-water hydraulics. U.S. Geol. Survey Prof.
Paper 708.
Lusczynski, Norbert J. 1961. Head and flow of ground water of variable
density. Journal of Geophysical Reserach, Vol. 66, No. 12.
National Oceanic and Atmospheric Administration. 1983. Tide tables
1984, east coast of North and South America including Greenland.
National Ocean Service.
5-1
-------
National Oceanic and Atmospheric Administration. 1984. Tide tables
1985, east coast of North and South America includiny Greenland.
National Ocean Service.
Peak, Harry M, Likie A. Register and Perry F. Nelson. 1972. Potential
ground-water supplies for Roanoke Island and the Dare County
beaches, North Carolina. North Carolina Department of Natural
Resources Report of Investigation No. 9.
Perrier, E.R. and A.C. Gibson. 1980. Hydrologic simulation on solid
waste disposal sites. U.S. Environmental Protection Agency
SW-868.
U.S. Environmental Protection Agency. 1979. Methods for chemical analy-
sis of water and wastes. USEPA Report 600/4-79-020.
U.S. Environmental Protection Agency. 1982. Environmental impact
statement, North Carolina barrier islands wastewater management,
technical reference document. Alternatives development report.
U.S. Federal Register Vol. 49, No. 209, October 26, 1984.
Wilder, H.B., T.M. Robison and K.L. Lindskov. 1978. Water resources of
northeast North Carolina. U.S. Geol. Survey Water Resources Inv.
77-81.
Winner, M.D. Jr. 1975. Ground-water resources of the Cape Hatteras
National Seashore, North Carolina. U.S. Geol. Survey Hydrologic
Atlas HA-540.
5-2
-------
APPENDIX A
6-1
-------
WELL CONSTRUCTION RECORDS
Well construction records have been completed for each well site in
each study area. These records are presented on the following pages.
The symbols used in these records are identified in Figure 1.
Land surface
\
Water table
Formation sand
Borehole
Protector pipe and cover
I
Cement
PVC pipe
Bentonite
Crushed stone and sand
PVC screen
Figure 1. Identification of symbols used in well construction records.
6-3
-------
WELL CONSTRUCTION RECORDS
FOR
KILL DEVIL HILLS
6-5
-------
WELL CONSTRUCTION RECORD
Site ID:
K1A
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and
are finished about one foot above land
Location:
Kill Devil Hills. NC
surface. The wells are enclosed at land
surface in steel pipes with locking caps.
Pro.iect No.:
172
Geologist:
T. Corwin, J. Fish
Predominant
Lithology
Tan to brown medium
sand
Gray to brown medium
to fine sand
Dense to very dense
gray fine sand
Gray fine sand with
some clay j
Silt and sand
Depth
bel ow
land
surface
(feet)
25
40
75
80
9
13
15
35.5
40.5
65
70
86.5
K1A1
r
i
Well Construction Details
K1A2
n
-*¦
"H h
K1A3
n
6-7
-------
WELL CONSTRUCTION RECORD
Site ID:
K1B
Well construction: The well is con-
structed of schedule 40 PVC pipe and is
finished about one foot above land surface.
The well is enclosed at land surface
in a steel pipe with a locking cap.
Client:
EPA
Location:
Kill Devil Hills. NC
Project No.:
172
Geologist:
T. Corwin
Predominant
Lithology
Brown fine to medium
_sand
Light gray fine sand
Depth
below
land
surface
(feet)
6
10
12
Well Construction Details
6-8
-------
WELL CONSTRUCTION RECORD
Site ID:
K1C
Well construction: The wells are con-
structed of schedule 40 PVC pipe and
are finished at land surface in utility
boxes. The wells are enclosed at land
surface in steel pipes with locking caps.
Client:
EPA
Location:
Kill Devil Hills. NC
Pro.iect No.:
172
Geologist:
T. Corwin, J. Fish
Predominant
Lithology
Light brown fine to
medium sand
Peat
Dense light gray fine
to medium sand
Depth
below
land
surface
(feet)
\iO
12
13
Silty fine sand
65
31
36|
40
56
61
70
Well Construction Details
K1C1
n if
n
K1C4
K1C5
••t •
-------
WELL CONSTRUCTION RECORD
Site ID: KID
Well construction: The well is con-
structed of schedule 40 PVC pipe and is
finished at land surface in a utility box.
The well is enclosed at land surface in a
steel pipe with a locking cap.
Client: EPA
Location: Kill Devil Hills, NC
Project No.: 172
Geologist: T. Corwin
6-10
-------
WELL CONSTRUCTION RECORD
Site ID:
K1E
Well construction: The wells are con-
structed of schedule 40 PVC pipe and
are finished about one foot above land
surface. The wells are enclosed at land
surface in steel pipes with locking caps.
CIient:
EPA
Location:
Kill Devil Hills. NC
Pro.iect No.:
172
Geologist:
T. Corwin, J. Fish
Predominant
Lithology
Organic silt a
Loose to firm light
gray fine sand
Firm to dense light
gray fine to medium
sand with some shell
fragments
Firm to very dense
gray fine to medium
sand
Gray silty fine sand
Very dense gray fine
sand
Depth
bel ow
land
surface
(feet)
3.5
35
55
75
95.9
9
12
K1E1
34
%
59
64
96.5
k-
Well Construction Details
K1E2
n
M—
K1E3
n
i
6-11
-------
WELL CONSTRUCTION RECORD
Site ID:
K2A
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and
are finished about one foot above land
Location:
Kill Devil Hills. NC
surface. The wells are enclosed at land
surface in steel pipes with locking caps.
Project No.:
172
Geologist:
T. Corwin, J. Fish
Predominant
Lithology
Firm to very dense
fine to coarse tan
sand
Fine to very dense
fine gray sand
Very dense tan fine
sand with some clay
and silty sand lenses
--80
Very dense gray fine
to coarse sand
Lenses of white, tan
and black medium to ,
coarse sand and clay/
Lenses of fine sand
and clay
Fine to coarse sand
with shells
Depth
bel ow
land
surface
(feet)
45
65
90
97
102
9
14
16
41
46
90
95
110
Well Construction Details
K2A1
K2A2
n
K2A3
•¦-I k
H h
6-12
-------
WELL CONSTRUCTION RECORD
Site ID:
K2B
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and
are finished about one foot above land
Location:
Kill Devil Hills, NC
surface. The wells are enclosed at land
surface in steel pipes with locking caps.
Pro.iect No.:
172
Geoloqist:
T. Corwin, J. Fish
Predominant
Lithology
Light brown fine to
medium sand
Dense to very dense
light gray fine to
medium sand
Depth
below
land
surface
(feet)
10
Interbedded clayey
silts and silty fine
sand
77
5
10
35
40
70
75
81.5
K2B1
t
h
H I-
Well Construction Details
K2B2
O
H h
K2B3
m
h
6-13
-------
WELL CONSTRUCTION RECORD
Site ID:
K2C
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and
are finished at land surface in utility
Location:
Kill Devil Hills. NC
boxes. The wells are enclosed at land
surface in steel pipes with locking caps.
Project No.:
172
Geologist:
T. Corwin, J. Fish
Predominant
Lithology
Light brown medium
sand
Light gray fine to
medium sand
Very dense light gray
fine sand with shell
fragments
Firm to very dense
light gray fine to
medium sand
Stiff gray sandy silt
Green to gray coarse
sand
Depth
bel ow
land
surface
(feet)
35
60
85
91
5
10
34
39
41
75
80
91.5
95
100
120
Well Construction Details
K2C1
K2C2
K2C3
H h
2".
fc-4-
K2C4
f
2"
nr
6-14
-------
WELL CONSTRUCTION RECORD
Site ID:
K2D
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and
are finished at land surface in utility
Location:
Kill Devil
Hills, NC
boxes. The wells are enclosed at land
surface in steel pipes with locking caps.
Pro.iect No.:
172
Geologist:
T. Corwin,
J. Fish
Predominant
Lithology
Light brown fine sand
Light gray fine sand
Clayey silt and siltyi
sand
Light gray fine to
medium sand
Gray fine to medium
sand with shells
Silt with some clay
Depth
bel ow
land
surface
(feet)
19
22
50
81
6
11
12
34
38
71
76
85
Well Construction Details
K2D2
ns
H h
H k
K2D3
*••• • J
> '
6-15
-------
WELL CONSTRUCTION RECORD
Site ID:
K2E
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and
are finished about one foot above land
Location:
Kill Devil Hills. NC
surface. The wells are enclosed at land
surface in steel pipes with locking caps.
Project No.:
172
Geologist:
T. Corwin, J. Fish
Predominant
Lithology
Brown fine to medium
sand with thin lenses
of peat /
Gray fine sand J
- -
Gray fine sand with
some silt
Gray fine to medium
sand
Silt and silty fine
sand
Light gray fine sand
Silty clay
Firm blue-gray clay
Depth
below
land
surface
(feet)
5
15
25
55
65
81
85
9 ^
v CZl.'
35.5
40.5
Well Construction Details
K2E1
K2E2
K2E3
H h
73
78
86.5
B1~
6-16
-------
WELL CONSTRUCTION RECORD
Site ID:
K3A
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and
are finished about one foot above land
Location:
Kill Devil Hills. NC
surface. The wells are enclosed at land
surface in steel pipes with locking caps.
Pro.iect No.:
172
Geologist:
T. Corwin, J. Fish
Predominant
Lithology
Light brown medium
sand
Light brown fine to
medium sand with shell
fragments
Gray fine sand with
shell fragments
Gray fine sand with a
trace of silt
Very dense light gray
fine sand
Very dense light gray
medium to coarse sand
Silty sand
Depth
bel ow
land
surface
(feet)
25
35
60
70
100
9
14
34.9
$9.5
40
55
60
61
93
98
106.5
Well Construction Details
K3A1
O
K3A2 K3A2B
H h
O
• m*
R
K3A3B
1
r—J*—
6-17
-------
WELL CONSTRUCTION RECORD
Site ID:
K3B
Well construction: The well is con-
Client:
EPA
structed of schedule 40 PVC pipe and is
finished about one foot above land
Location:
Kill Devil Hills. NC
surface. The well is enclosed at land
surface in a steel pipe with a locking
cap.
Project No.:
172
Geologist:
T. Corwin, J. Fish
Predominant
Depth
below
land
Well Construction Details
Lithology
surface
(feet)
K3B1
Light brown fine to
medium sand j
Gray fine to medium
sand
3
4
9
i
i
r
I
2"
k-
6-18
-------
WELL CONSTRUCTION RECORD
Site ID:
K3C
Well construction: The well is con-
CIient:
EPA
structed of schedule 40 PVC pipe and is
finished about one foot above land
Location:
Kill Devil Hills. NC
surface. The well is enclosed at land
surface in a steel pipe with a locking
Pro.iect No.:
172
cap.
Geologist:
T. Corwin, J. Fish
Predominant
Lithology
Light brown fine to
medium sand
Depth
below
land
surface
(feet)
Well Construction Details
6-19
-------
WELL CONSTRUCTION RECORD
Site ID:
K3D
Well construction: The wells are
CI lent:
EPA
constructed of schedule 40 PVC pipe.
The wells are enclosed at land surface
Location:
Kill Devil Hills. NC
in steel pipes with locking caps.
Project No.:
172
Geologist:
T. Corwin. J. Fish
Predominant
Lithology
LlgJjt brown fine to
medium sand
Sandy organic silt
16
'18
Gray fine sand
Sandy silt
Depth
bel ow
land
surface
(feet)
*O.S
8
13
13.5
26.5
46.5
47
74
79
86.5
Well Construction Details
2±
~T
K3D1
i
$i_K3D2
JX
7
T
K3D3B
(
¦Si
6-20
-------
WELL CONSTRUCTION RECORD
Site ID:
K3E
Well construction: The well Is con-
Client:
EPA
structed of schedule 40 PVC pipe and 1s
finished about one foot above land
Location:
Kill Devil Hills. NC
surface. The well 1s enclosed at land
surface 1n a steel pipe with a locking
cap.
Pro.iect No.:
172
Geologist:
T. Corwln, J. F1sh
Predominant
Lithology
Brown fine to medium
sand y
Gray fine to medium
sand
Depth
below
land
surface
(feet)
6.5
4.5
9.5
10
Well Construction Details
K3E1
6-21
-------
WELL CONSTRUCTION RECORD
Site ID:
K3F
Well construction: The well is con-
Client:
EPA
structed of schedule 40 PVC pipe and is
finished about one foot above land
Location:
Kill Devil Hills. NC
surface. The well is enclosed at land
surface in a steel pipe with a locking
cap.
Project No.:
172
Geologist:
T. Corwin, J. Fish
Predominant
Lithology
Depth
bel ow
land
surface
(feet)
Well Construction Details
K3F1
i
Light brown fine to
medium sand
6
11
12
I
6-22
-------
WELL CONSTRUCTION RECORD
Site ID:
K3G
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and
are finished about one foot above land
Location:
Kill Devil Hills. NC
surface. The wells are enclosed at land
surface in steel pipes with locking caps.
Pro.iect No.:
172
Geoloaist:
T. Corwin, J. Fish
Predominant
Lithology
Light brown fine sand
Light gray fine sand
Light gray fine sand
with shell fragments
Light gray to brown
fine to medium sand
Gray fine sand with
clayey sand and silty
sand lenses
Clayey silt
Depth
bel ow
land
surface
(feet)
10
25
65
81
4.5
9.5
15
34.5
39.5
41.5
70
75
87
K3G1
O
I—
Well Construction Details
K3G2
O
¦¦-A I—
K3G3
rt
6-23
-------
WELL CONSTRUCTION RECORDS
FOR
ATLANTIC BEACH
6-25
-------
WELL CONSTRUCTION RECORD
Site ID:
A1A
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and are
finished about one foot above land surface.
Location:
Atlantic Beach, NC
The wells are enclosed at land surface in
steel pipes with locking caps.
Pro.iect No.:
172
Geologist:
T. Corwin, J. Fish
Predominant
Li thology
Tan fine to medium
sand
Gray fine to medium
sand
Gray fine to medium
sand and shells
Soft gray clay
Depth
bel ow
land
surface
(feet)
6
11
15
20
46
37
42
50
Well Construction Details
A1A1
v
A1A3
r=ft
"H h
. 4 :
H h
6-27
-------
WELL CONSTRUCTION RECORD
Site ID:
A1B
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and are
finished about one foot above land surface.
Location:
Atlantic Beach, NC
The wells are enclosed at land surface in
steel pipes with locking caps.
Pro.iect No.:
172
Geologist:
T. Corwin, J. F1sh
Predominant
Lithology
Tan fine sand
Gray silty fine sand
( 1-24
Tan to gray fine sand
and shells
36
| Gray_c1ay_ and_si
Silty fine sand
Depth
below
land
surface
(feet)
12
6
11
13
30
35
42
Well Construction Details
A1B1
in
A1B3
f—L_
y
6-28
-------
WELL CONSTRUCTION RECORD
Site ID:
A1C
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and are
finished about one foot above land surface.
Location:
Atlantic Beach. NC
The wells are enclosed at land surface in
steel pipes with locking caps.
Pro.iect No.:
172
Geoloqlst:
T. Corwin
Predominant
Lithology
Tan fine to medium
sand and shells
Interbeded layers of ^
fine sand and sllty
fine sand
Gray fine sand and
shells
Gray sllty fine sand
Depth
below
land
surface
(feet)
24
32
6
11
15
27
32
37
Well Construction Details
A1C1
A1C3
ff~R
V
s
"—I h-
ri *il
6-29
-------
WELL CONSTRUCTION RECORD
Site ID:
AID
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and are
finished at land surface in utility boxes.
Location:
Atlantic Beach, NC
The wells are enclosed at land surface in
steel pipes with locking caps.
Project No.:
172
Geologist:
J. Fish
Predominant
Lithology
Fine sand and gravel
/]
Gray fine sand
Gray fine sand with
some shells
Gray clay interbedded
with fine sand* /
Gray fine sand with
shells
Tan fine to coarse
sand and shells
1
This layer
was encountered
only in borehole A1D2.
Depth
below
land
surface
(feet)
7
18
49
52
70
8
13
20
35
40
52
91
96
110
A1D1
Well Construction Details
A1D2
w-^'r
.• /
u ##
H (*-
"V
A1D3
k
6-30
-------
WELL CONSTRUCTION RECORD
Site ID:
A2A
Well construction: The wells are con-
CIient:
EPA
structed of schedule 40 PVC pipe and are
finished about one foot above land surface.
Location:
Atlantic Beach, NC
The wells are enclosed at land surface in
steel pipes with locking caps.
Pro.iect No.:
172
Geoloqist:
T. Corwin, J. Fish
Predominant
Lithology
Depth
below
land
surface
(feet)
Well Construction Details
A2A1
A2A3
I
I
A2A4
S 0
Tan fine sand
Gray silty fine sand^
Gray fine sand with
some shells
Soft gray clay with
lenses of gray fine
sand
14
16.5
32.5
58
Fine sand and shells
8.5
13.5
15
27
32
41.5
H h
*' ^ .'4
H h
i
*
\
62.9
67.9
70
XJ
H h
6-31
-------
WELL CONSTRUCTION RECORD
Site ID:
A2B
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and are
finished at land surface in utility boxes.
Location:
Atlantic Beach, NC
The wells are enclosed at land surface in
steel pipes with locking caps.
Project No.:
172
Geologist:
T. Corwin, 0. Fish
Predomi nant
Lithology
Light brown fine sand
Silty fine sand ^/|
Gray fine sand with
some occurrences of
silt and shells
Interbedded gray silty
clay, silt and silty
fine sand
Depth
below
land
surface
(feet)
6
7.5
32
72
Greenish-gray fine to
coarse sand and shells
see next page
110
a
12
25
30|
37
85
90
Well Construction Details
A2B1
A2B3
H h
v
H h
2'1
A2B4
jcsanJ
o
A.'
A
* •.
».. •
. * ••
' • / - 4
6-32
-------
WELL CONSTRUCTION RECORD
Site ID:
A2B (cont'd)
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and are
finished at land surface in utility boxes.
Location:
Atlantic Beach, NC
The wells are enclosed at land surface in
steel pipes with locking caps.
Pro.iect No.:
172
Geologist:
T. Corwin, J. Fish
Predomi nant
Lithology
Green silty fine sand
164
Limestone
Depth
below
land
surface
(feet)
165
Well Construction Details
A2B4
-n/^
-V
•' : A 1
4"0
' 4 .
' • * 4
6-33
-------
WELL CONSTRUCTION RECORD
Site ID:
A2C
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and are
finished at land surface in utility boxes.
Location:
Atlantic Beach, NC
The wells are enclosed at land surface in
steel pipes with locking caps.
Project No.:
172
Geoloqist:
T. Corwin
Predominant
Lithology
Tan to gray fine to
medium sand
Gray fine sand
Gray clayey silt and
sllty fine sand
Gray fine to medium
sand and shells
Depth
below
land
surface
(feet)
10
23
1
13
17
60
22
31.5
65
70
75
Well Construction Details
A2C1
A2C3
n
A2C4
V »
f • I,
ff
H I—
f.
H b
6-34
-------
WELL CONSTRUCTION RECORDS
FOR
PINE KNOLL SHORES
6-35
-------
WELL CONSTRUCTION RECORD
Site ID:
P1A
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and are
finished about one foot above land surface.
Location:
P1ne Knoll Shores, NC
The wells are enclosed at land surface in
steel pipes with locking caps.
Pro.iect No.:
172
Geologist:
J. Fish, T. Corwln
Predominant
Llthology
Depth
below
land
surface
(feet)
Tan fine to medium
sand
Fine to medium gray
sand with some shells
Gray fine sand
Gray clay with some
fine sand
40.4
62
12
17
21
35
40
45
55
60
66.5
Well Construction Details
6-37
P1A3
f
'I
¦f
*
« •»
Hr
-------
WELL CONSTRUCTION RECORD
Site ID: P1B
Well construction: The well is con-
structed of schedule 40 PVC pipe and is
finished about one foot above land surface
The well is enclosed at land surface in a "
steel pipe with a locking cap.
Client: EPA
Location: Pine Knoll Shores, NC
Project No.: 172
Geoloqist: J. Fish
Predominant
Lithoiogy
Tan fine sand with
some she!1s
Depth
below
land
surface
(feet)
11.6
16.6
19
Well Construction Details
P1B1
n
* r ' ' |
2'<-^
6-38
-------
WELL CONSTRUCTION RECORD
Site ID:
PIC
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and are
finished at land surface in utility boxes.
Location:
Pine Knoll Shores, NC
The wells are enclosed at land surface in
steel pipes with locking caps.
Pro.iect No.:
172
Geologist:
J. Fish, T. Corwin
Predominant
Lithology
Tan to brown fine sand
Gray to green fine
sand with lenses of
organic silt
Gray fine to medium
sand with occurrences
of shells
Interbedded layers of
gray clay, silt and
sllty fine sand
Fine to medium sand
and shells
Green s11t and fine
sand
Depth
below
land
surface
(feet)
6.5
111.5
58
68
73
12
13
28
33
35
50.8
55.8
|66.5
68
73
79
Well Construction Details
P1C1
nt
P1C2
P1C3
P1C4
Hh
H
6-39
-------
WELL CONSTRUCTION RECORD
Site ID:
P1D
Well construction: The well is con-
CIient:
EPA
structed of schedule 40 PVC pipe and is
finished at land surface in a utility box.
The well is enclosed at land surface in a
steel pipe with a locking cap.
Location:
Pine Knoll Shores, NC
Project No.:
172
Geologist:
J. Fish
6-40
Predominant
Lithology
Dark brown fine sand
Light brown fine sand
with shells
Depth
below
land
surface
(feet)
6
10
15
Well Construction Details
v
P1D1
ruf
H I—
-------
WELL CONSTRUCTION RECORD
Site ID:
PIE
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and are
finished about one foot above land surface.
Location:
Pine Knoll Shores, NC
The wells are enclosed at land surface in
steel pipes with locking caps.
Pro.iect No.:
172
Geologist:
J. Fish, T. Corwin
Predominant
Lithology
Brown to tan fine sand
Depth
bel ow
land
surface
(feet)
Gray fine to medium
sand with occurrences
of shells
12
Interbedded gray clay,
clayey silt and silty
sand
57
12
15
29
34
35
51
56
61.5
P1E1
H h
Well Construction Details
P1E2
I
Hh
6-41
P1E3
ft
i h
-------
WELL CONSTRUCTION RECORD
Site ID:
P2A
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and are
finished at land surface in utility boxes
The wells are enclosed at land surface in"
steel pipes with locking caps.
Location:
Pine Knoll Shores, NC
Pro.iect No.:
172
Geologist:
T. Corwin, J. Fish
-------
WELL CONSTRUCTION RECORD
Site ID:
P2B
Well construction: The well is con-
Client:
EPA
structed of schedule 40 PVC pipe and is
finished about one foot above land surface.
Location:
P1ne Knoll Shores. NC
The well is enclosed at land surface in a
steel pipe with a locking cap.
Project No.:
172
Geoloqlst:
J. F1sh
Predominant
Depth
below
land
Well Construction Details
Llthology
surface
(feet)
P2B1
Tan to light brown
fine sand
9
14
16.5
i
n «
12
I'hJ
Gray fine to medium
sand with some shells
b"*! *-* •!
i
H b
6-43
-------
WELL CONSTRUCTION RECORD
Site ID:
P2C
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and are
finished about one foot above land surface.
Location:
Pine Knoll Shores. NC
The wells are enclosed at land surface in
steel pipes with locking caps.
Project No.:
172
Geologist:
T. Corwin, J. Fish
Predominant
Lithology
Light brown fine sand
Dark brown fine sand ^
and organic silt A
Gray fine sand
Gray fine sand and
sandy silt
Gray clay
Gray silty sand and
shells
Depth
bel ow
land
surface
(feet)
11
14
40
45
55
5.6
15
30
32
35
37
51.5
I64.5
69.5I
75
Well Construction Details
P2C1
P2C2
nfr^to
M
q •• + V ».B
P2C3
I
P2C4
/«•
H
I
•*—
6-44
-------
WELL CONSTRUCTION RECORD
Site ID:
P2D
Well construction: The well is con-
Client:
EPA
structed of schedule 40 PVC pipe and 1s
finished about one foot above land surface.
Location:
Pine Knoll Shores. NC
The well 1s enclosed at land surface In a
steel pipe with a locking cap.
Project No.:
172
Geologist:
T. Corwin
6-45
-------
WELL CONSTRUCTION RECORD
Site ID:
P2E
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and are
finished about one foot above land surface.
Location:
Pine Knoll Shores, NC
The wells are enclosed at land surface in
steel pipes with locking caps.
Pro.iect No.:
172
Geologist:
T. Corwin
Predominant
Lithology
Silt (Fill material)
Brown peat and silt
Tan to light gray fine
sand with some silt f
Gray fine to medium
sand with shells
Gray fine sand and
silty fine sand
Soft gray clay
•36.3
-46 .a
Depth
below
land
surface
(feet)
5.5
6.5
16.5
8
13
15
22
27
30
37
42
51.5
Well Construction Details
P2E2
a i-<
#9
P2E3
O
b
W/>
"A V-
6-46
-------
WELL CONSTRUCTION RECORDS
FOR
SURF CITY
6-47
-------
WELL CONSTRUCTION RECORD
Site ID:
S1A
Well construction: The wells are con-
CIient:
EPA
structed of schedule 40 PVC pipe. Wells
S1A1 and S1A2 are finished at land surface
Location:
Surf City. NC
in utility boxes and well S1A3 is finished
about one foot above land surface. The
Pro.iect No.:
172
wells are enclosed at land surface in
steel pipes with locking caps.
Geologist:
J. Fish, T. Corwin
Predominant
Lithology
Tan fine to medium
sand
"white and brown fine
to coarse sand and
shells
Tan fine to medium
sand and shells
Gray clay
Gray limestone
Tan sandstone
Depth
below
land
surface
(feet)
10
20
37
40.5
50
9.7
14.71
15
32
37
41
55
60
Well Construction Details
S1A1
"¦A (-
6-49
S1A2
O
H I*-
S1A3
H h
-------
WELL CONSTRUCTION RECORD
Site ID:
SIB
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and are
finished at land surface in utility boxes
The wells are enclosed at land surface in"
steel pipes with locking caps.
Location:
Surf City, NC
Project No.:
172
Geologist:
J. Fish, T. Corwin
Predominant
Lithology
Brown fine to medium
sand and shells
"Brown "to" grajMnedTum
to coarse sand and
shells
Gray tine to medium
sand
Gray fine silty sand
Gray limestone
Tan sandstone
Depth
below
land
surface
(feet)
15
25
33
36
53
6
11
16
26
31
33
65
70
Well Construction Details
S1B1
S1B2
S1B3
•—I k-
"H b-
6-50
nr
%
*
i
i.*.
H h
-------
WELL CONSTRUCTION RECORD
Site ID:
S3A
Well construction: The wells are con-
Client:
EPA
structed of schedule 40 PVC pipe and are
finished about 0.5 feet above land surface.
Location:
Surf City, NC
The wells are enclosed at land surface in
steel pipes with locking caps.
Pro.iect No.:
172
Geologist:
J. Fish. T. Corwin
Predominant
Lithology
Tan to brown fine to
medium sand and shells
Gray fine to coarse
sand and shells
Tan medium to coarse
sand and shells
Fine sandy silt
Gray limestone
Interbedded gray
limestone, tan
sandstone and very
fine sand
Depth
below
land
surface
(feet)
10
|25
34
38
56
12.4
17.4]
20
26.5|
31
34
60
65
70
Well Construction Details
S3A1
S3A2
S3A3
1
n
-t i-
, a • v
H h
6-51
-------
WELL CONSTRUCTION RECORD
Site ID: S3B
Well construction: The wells are con-
structed of schedule 40 PVC pipe. Well
S3B1 1s finished about 1.5 feet above land
surface while wells S3B2, S3B3, S3B4 and
S3B5 are finished at land surface 1n
utility boxes. The wells are enclosed at
land surface 1n steel pipes with locking
caps.
Client: EPA
Location: Surf City, NC
Project No.: 172
Geologist: J. F1sh. T. Corwln
Predominant
Llthology
Tan fine to medium
sand and she!1s
Gray fine to medium
sand and shells
S11ty clay
Light gray limestone
Interbedded gray
limestone and green
sandstone
Green sandstone
see next page
Depth
bel ow
land
surface
(feet)
6
31
\34
60
75
113
-------
WELL CONSTRUCTION RECORD
Site ID: S3B (cont'd)
Well construction: The wells are con-
structed of schedule 40 PVC pipe. Well
S3B1 1s finished about 1.5 feet above land
surface while wells S3B2, S3B3, S3B4 and
S3B5 are finished at land surface 1n
utility boxes. The wells are enclosed at
land surface 1n steel pipes with locking
caps.
Client: EPA
Location: Surf C1tv. NC
Project No.: 172
Geologist: J. F1sh. T. Corwln
Predomlnant
Llthology
Gray limestone
Depth
below
land
surface
(feet)
119
124
135
Well Construction Details
S3B4
j
V"—
H h
6-53
-------
WELL CONSTRUCTION RECORD
Site ID:
S3C
Well construction: The wells are con-
structed of schedule 40 PVC pipe and are
finished about one foot above land surface
The wells are enclosed at land surface 1n '
steel pipes with locking caps.
Client:
EPA
Location:
Surf City, NC
Project No.:
172
Geologist:
J. Fish, T. Corwin
-------
APPENDIX B
6-55
-------
LITHOLOGY SAMPLING RECORDS
Lithology sampling records have been completed for each monitoring
well site in each study area. At some sites multiple wells were used to
complete the lithology record for the site.
meaning:
In the records that follow, the column headings have the following
Depth:
Sampler blows:
Percent Recovery:
Sample ID:
Sample description:
Depth in feet below land surface.
The number of blows
split-spoon sampler
ground. Testing is
inch increments,
used in this test
required to drive a
18 inches into the
divided into three six-
The maximum number of blows
per six-inch increment is
50. The depth the sampler was driven in the
six-inch increment is recorded in parentheses
if 50 blows were reached and further sampling
for that interval is discontinued.
The percentage of sample recovered in the
split-spoon sampler.
The identification number asigned to the
sample.
A physical description of the material
encountered as drilling progressed. A
description of the material retrieved by
sampling is described next to the sample ID
number.
6-57
-------
LITHOLOGY SAMPLING RECORDS
FOR
KILL DEVIL HILLS
6-59
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 3
Well ID: K1A3
Date well drilled: Ma.y 9, 1984
Client: EPA
Borehole depth: 86.5 ft
Location: Kill Devil Hills. NC
DrilUnq method: Mud rotary
Pro.lect No.: 172
SampHnq method: Split spoon
Geoloolst: J. Fish
Driller: A-C Borinas. Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
2/3/6
100
1
Tan to brown medium sand
5 —
1/1/2
65
2
Tan to brown medium sand
10 -
8/8/12
20
3
Tan to brown medium sand
15 -
11/12/K
35
4
Light brown fine to coarse sand
with some shell fragments
20 -
19/25/26
70
5
Very dense light brown fine sand
25 -
16/27/2*
0
6
No recovery
———— !
6-61
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 3
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
35 —f
14/19/17
8/8/10
40 -4
21/37/38
45
9/16/24
50 -4
10/32/49
55 —f
15/17/2
60 —f
25/47/23
65
15/26/30
85
50
55
65
70
85
60
70
TU"
TT
TT
TT
TT
Gray to brown fine to medium sand
Gray to brown fine to medium sand
Very dense gray fine to medium sand
Dense gray fine sand
Gray fine sand
Dense gray fine sand
Very dense gray fine sand
Very dense gray fine sand
6-62
-------
LITHOLOGY SAMPLING RECORD
Page 3 of 3
Depth
(feet)
Sampler
B1 ows
Percent
Recovery
Sample
ID
Sample Description
70
U1
fH
00
rH
rH
60
15
Dense gray fine sand
75 -
5/7/5
85
16
Gray fine sand with some clay
80 —
Loose gray fine sand with some silt
2/4/5
100
17
85 -
5/1/4
40
IS
Soft gray silt and sand
6-63
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: K1B1
Date well drilled: April 26, 1984
Client: EPA
Borehole depth: 12.0 ft
Location: Kill Devil Hills, NC
Drilling method: Auger
Pro.iect No.: 172
Sampling method: Cuttings Examination
Geologist: T. Corwin
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
Brown fine to medium sand from
0 to 6 ft
5 —
Light gray fine sand from
6 to 12 ft
10 —
12 -
6-64
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: K1C2 (Replaced with K1C4)
Date well drilled: May 1, 1984
Client: EPA
Borehole depth: 41.5 ft
Location: Kill Devil Hills. NC
Drillinq method: Mud rotary
Project No.: 172
Samplinq method: Split spoon
Geologist: T. Corwin
Driller: A-C Borinqs, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
1/1/1
50
1
Very loose light brown fine sand
5 —
2/3/4
65
2
Loose light brown fine to medium sand
10 -
Very loose light brown to gray fine sand
1/1/1
45
3
15 -
Peat encountered between 10.5 ft and 12 ft
16/19/32
70
4
Dense light gray fine sand
20 -
13/22/2E
55
5
Light gray fine sand
25 -
13/34/48
85
6
Very dense light gray fine sand
6-65
-------
LITHOLOGY SAMPLING RECORD
2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
30
14/27/31
65
7
Dense light gray fine to medium sand
35 -
Dense light gray fine sand with some
shell fragments
17/26/4C
70
8
40 —
Dense light gray fine to medium sand
12/17/3C
55
9
6-66
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: K1C3 (Replaced with K1C5)
Date well drilled: May 2, 1984
Client: EPA
Borehole depth: 86.5 ft
Location: Kill Devil Hills, NC
Drillinq method: Mud rotary
Pro.iect No.: 172
Samplinq method: Split spoon
Geologist: T. Corwin
Driller: A-C Borinqs, Inc.
Depth
(feet)
Sampler
(Blows)
Percent
Recovery
Sample
ID
Sample Description
45
26/47/
100
10
Dense light gray fine to medium sand
50 —
50(4")
with some coarse sand and shell
22/39/
50(5")
70
11
Dense light gray fine sand
55 —
Light gray coarse sand with shells
near top of sample and light gray fine
sand near bottom of sample
16/28/5C
100
12
60 —
9/11/22
50
13
Dense light gray fine sand
65 -
10/14/1*
55
14
Dense light gray silty fine sand
70 -
10/16/2C
65
15
Firm light gray silty fine sand
6-67
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
75
8/11/13
90
16
Firm light gray s11ty fine sand
80 -
Dense gray sllty fine sand with a
trace of clay at bottom of sample
10/16/13
55
17
85 -
3/4/12
100
18
Firm dark gray clayey fine sand
See log for well K1C2 for sampling
from land surface to 40 ft
.... . .
6-68
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID:
K1D1
Date well drilled: April 27, 1984
CI lent:
EPA
Borehole depth: 13.0 ft
Location:
Kill Devil Hills. NC
Drilllnq method: Auqer
Pro.iect No.:
172
SampHnq method: Cuttlnqs Examination
Geoloqlst:
J. F1sh
Driller: A-C Borinqs, Inc.
Depth
Sampler
Percent
Sample
(feet)
Blows
Recovery
ID
Sample Description
0
5 —
Light brown fine to medium sand
from 0 to 13 ft
10 -
13 —
6-69
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 3
Well ID: K1E3
Date well drilled: April 27, 1984
Client: EPA
Borehole depth: 96.5 ft
Location: Kill Devil Hills, NC
Drilling method: Mud rotary
Pro.iect No.: 172
Sampling method: Split spoon
Geolooist: T. Corwin
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
1/1/1
100
1
Organic silt
5 —
2/3/3
50
2
Gray fine sand
10 —
3/4/5
65
3
Loose gray fine sand
15 —
3/3/7
75
4
Dark gray clayey silt to 15.3 ft,
then loose gray fine sand
20 —
3
100
5
Gray sandy silt to silty fine sand
25 —
9/8/7
55
6
Firm light gray fine sand with a
trace of shell fragments
6-70
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 3
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
30
8/8/6
45
7
Firm light gray fine sand with a
35 -
trace of shell fragments
1/5/7
75
8
Firm gray medium sand with some
large shell fragments
40 -
5/10/11
45
9
Firm light gray medium sand with
some shell fragments
45 -
15/25/2S
35
10
Very dense light gray fine to medium
sand with some shell fragments
50 -
16/27/32
100
11
Dense light gray fine to medium sand to
50.3 ft, then shell fragments with coarse
55 -
sand to 50.8 ft, then dense light gray
fine to medium sand
20/23/3'
100
12
Dense gray medium sand with shell frag-
ments to 55.8 ft, then dense gray fine
60 -
sand
20/23/3?
65
13
Very dense gray fine sand
65 -
9/11/15
55
14
Firm gray fine sand
6-71
-------
LITHOLOGY SAMPLING RECORD
Page 3 of 3
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
70
18/26/32
70
15
Very dense green to gray fine sand
75
1/1/1
100
16
Very soft gray silty fine sand
80 ~~
8/9/8
100
17
Gray silty fine sand to 81.3 ft,
then stiff gray sandy silt
85 -
2/3/6
100
18
Loose gray silty fine sand
90 -
1/1/9
100
19
Soft gray sandy silt to 90.9 ft,
then firm gray fine sand
95 —
Gray sandy silt to 95.4 ft, then
very dense gray fine sand
26/32/35
90
20
6-72
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 3
Well ID: K2A3
Date well drilled: May 10, 1984
Client: EPA
Borehole depth: 110 ft
Location: Kill Devil Hills. NC
Drilling method: Mud rotary
Project No.: 172
Samplinq method: Split spoon
Geologist: J. Fish
Driller: A-C Borings. Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
6/8/7
100
1
Firm tan fine to medium sand
5 -
3/6/8
70
2
Firm tan fine to medium sand
10 —
5/5/14
95
3
Firm light brown fine to coarse sand
15 —
Very dense light brown fine to coarse sand
8/22/41
35
4
20 —
Very dense tan fine to coarse sand with
shell fragments
32/47/
50(5")
80
5
25 -
27/30/3C
75
6
Very dense tan fine sand
6-73
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 3
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
30
17/24/3'
70
7
Very dense tan fine sand
35 —
Very dense tan fine sand
21/27/3J
50
8
Very dense tan fine to medium sand
40 —
22/33/3S
70
9
45 -
22/31/
50(6")
70
10
Very dense gray fine sand
50 —
20/31/42
60
11
Very dense gray fine sand
55 —
20/28/3-
85
12
Very dense gray fine sand
60 —
2/6/18
100
13
Firm gray fine sand
65 —
18/32/
50(5.5")
80
14
Very dense tan fine sand
6-74
-------
LITHOLOGY SAMPLING RECORD
Page 3 of 3
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
70
39/50
90
15
Very dense tan fine sand with some clay
75 -
(5")
50(5")
100
16
Very dense tan fine sand with lenses of
gray silty sand
80 —
50(4.5")
100
17
Very dense light gray fine to coarse sand
85 -
40/50
(4")
100
18
Very dense light gray fine to coarse sand
90 —
50(5")
100
19
Very dense white, tan and black medium to
coarse sand
95 -
Fine to coarse sand from 92 ft to 97 ft
100 —
Alternating layers of fine sand and gray
clay from 97 ft to 102 ft
105 —
Fine to coarse sand with shells from
102 ft to 110 ft
110
6-75
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 3
Well ID: K2B3
Date well drilled: May 13, 1984
Client: EPA
Borehole depth: 81.5 ft
Location: Kill Devil Hills, NC
Drilling method: Mud rotary
Pro.iect No.: 172
Sampling method: Split spoon
Geologist: T. Corwin
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
Light brown fine to medium sand from
land surface to 7 ft
5 —
10 —
Gray to brown fine to medium sand from
7 ft to 10 ft
4/4/8
40
3
Firm light gray fine to medium sand
15 —
16/23/2/
30
4
Dense light gray fine to medium sand
20 -
14/25/21
55
5
Dense light gray fine to medium sand
25 —
17/20/1"
55
6
Dense light gray fine sand
6-76
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 3
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
30
15/27/4C
65
7
Very dense light gray medium to
35 —
coarse sand
23/50
(4")
100
8
Very dense light gray fine sand
40 -
10/24/3-
75
9
Very dense light gray fine to medium
sand
45 -
20/43/
50(3")
95
10
Very dense light gray fine sand with
shell fragments
50 -
24/40/
50(5")
80
11
Very dense light gray fine sand
55 -
60 -
13/19/2E
85
12
Dense gray medium sand
65 -
6-77
-------
LITHOLOGY SAMPLING RECORD
Page 3 of 3
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
70
20/50
70
13
Very dense light gray medium sand with
(4")
shell fragments
75 —
80
Clayey silt and silty sand from 77 ft
to 80 ft
1/1/1
100
14
Interbedded clayey silts and silty fine
sand
6-78
-------
LITHOLOGY SAMPLING RECORD Page 1 of 2
Well ID: K2C2
Date well drilled: April 24, 1984
Client: EPA
Borehole depth: 41.1 ft
Location: Kill Devil Hills, NC
Drilling method: Hollow stem auaer
Project No.: 172
Samplinq method: Split spoon
Geoloqist: T. Corwin
Driller: A-C Borings. Inc.
Depth
(feet)
Sampler
Blows
5 -4
1/2/5
1/1/1
10 -4
2/1/2
15
2/5/9
20 -4
8/26/38
25 -4
20/30/42
Percent
Recovery
75
85
65
75
85
100
Sample
ID
Sample Description
Light brown medium sand
Very loose gray fine sand
Light gray fine to medium sand
Light gray fine to medium sand
Light gray fine to medium sand
Light gray fine to medium sand
6-79
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
30
9/14/41
35 —
40 -•
24/50
(4.5")
21/39/
50(5")
100
85
75
Light gray fine to medium sand
Light gray fine to medium sand with
some shell fragments
Light gray medium to coarse sand with
some shell fragments
6-80
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: K2C3
Date well drilled: April 24-25, 1984
Client: EPA
Borehole depth: 91.5 ft
Location: Kill Devil Hills, NC
Drilling method: Mud rotary
Project No.: 172
Sampling method: SpVt spoon
Geologist: T. Corwin
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
45
9/34/50
65
10
Light gray fine sand with shell fragments
50 —
Very dense light gray fine sand with a
trace of she!1 fragments
22/34/5Q
70
11
55 -
Very dense light gray fine sand with a
trace of shell fragments
31/50
(4")
35
12
60 —
8/9/14
65
13
Firm light gray fine sand
65 -
Very dense light gray fine to medium sand
9/30/
50(4.5")
60
14
70 -
Very dense light gray to brown fine to
medium sand
1/25/41
55
15
6-81
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
75
37/50
0
16
No recovery
80 —
(5")
39/50
(3.5")
65
17
Very dense light gray fine to coarse sand
with a trace of shell fragments
85 —
1/1/1
45
18
Gray silt with a trace of clay and
some sand
90 —
6/5/6
55
19
Stiff gray sandy silt
Green to gray coarse sand observed from
cuttings for well K2C4 between 91 and 120
ft
See log for well K2C2 for sampling from
land surface to 40 ft
6-82
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 3
Well ID: K2D3
Date well drilled: AdHI 28. 1984
Client: EPA
Borehole depth: 85.0 ft
Location: Kill Devil Hills, NC
Drilling method: Mud rotary
Pro.iect No.: 172
Sampling method: SDlit spoon
Geologist: T. Corwin
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
Light brown fine sand to 5 ft
5 —
10 -
Light gray fine to medium sand
from 5 to 19 ft
15 -
20 —
Pushed
sampler
100
1
Dark gray silty clay with fine sand
25 -
Light gray fine sand
6-83
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 3
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
30
35 -
Light gray fine sand
40 -
Light gray fine to medium sand
45 -
50 -
Gray fine to coarse sand with shells
55 -
60 —
Gray fine to medium sand with shells
65 -
6-84
-------
LITHOLOGY SAMPLING RECORD
Page 3 of 3
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
70
Gray medium sand with shells
75 -
80 -
Gray medium sand with shells
Gray silt with some clay from 81 to 85 ft
85 -
6-85
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 3
Wen ID:
K2E3
Date well drilled: April 26, 1984
CIient:
EPA
Borehole depth: 86.5 ft
Location:
Kill Devil Hills, NC
Drilling method: Mud rotary
Pro.iect No.:
172
Sampling method: Split spoon
Geologist:
J. Fish
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
3/3/3
65
1
Brown fine to medium sand with thin
lenses of peat
5 —
3/2/2
50
2
Brown to gray fine to medium sand
10 —
6/6/3
100
3
Gray fine sand
15 —
2/1/1
20
4
Gray fine sand with some si^
20 -
9/9/10
65
5
Gray fine sand with a trace of silt
25 -|
4/7/9
45
6
Gray fine to medium sand
6-86
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 3
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
30
1/8/7
85
7
Gray fine sand with shell fragments
35 -
8/7/9
35
8
Gray fine sand
40 -
2/4/9
40
9
Gray fine sand
45 -
1/19/32
65
10
Gray fine sand
50 -
14/20/16
Gray medium to coarse sand with shell
fragments
10
11
55 -
4/5/5
100
12
Dark brown organic silt to 56.2 ft,,
then brown fine sand
60 -
9/21/43
85
13
Brown fine sand to silty fine sand
65 -
23/50
(6")
65
14
Very dense gray fine sand
6-87
-------
LITHOLOGY SAMPLING RECORD
Page 3 of 3
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
70
12/50
65
15
Very dense light gray fine sand
75 —
(5")
27/44/
50(4")
60
16
Very dense light gray fine sand
80 -
23/16/9
35
17
Light gray fine sand
85 -
Silty clay at 81 ft
3/4/8
100
18
Firm blue-gray clay
6-88
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LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: K3A3 (Replaced with K3A3B)
Date well drilled: April 11, 1984
Client: EPA
Borehole depth: 56.5 ft
Location: Kill Devil Hills* NC
Drillinq method: Hollow stem auqer
Project No.: 172
Samplinq method: Split spoon
Geologist: J. Fish
Driller: A-C Borinqs, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
2/2/3
45
1
Light brown medium sand
5
7/7/7
60
2
Light brown fine to medium sand
shell fragments
with
10 -
2/3/6
with
80
3
Light brown fine to coarse sand
shell fragments
15 —
11/18/36
with
50
4
Light brown fine to medium sand
shell fragments
20 -
with
20/29/3-
50
5
Light brown fine to medium sand
shell fragments
25 -
22/28/3f
25
6
Gray to brown fine sand with
shell fragments
6-89
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
30
22/40/
50(2.5")
50
7
Gray fine sand with shell fragments
35 -
Gray fine sand with shell fragments and
a trace of silt
40/50
(4.5")
50
8
40 —
No recovery
22/46/
50(3")
0
9
45 —
Gray fine sand with a trace of silt
14/21/4S
35
10
50 —
6/14/21
90
11
Gray fine sand with a trace of silt
55 —
1/7/20
60
12
Gray fine sand with a trace Af silt
6-90
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID:
K3A3B
Date well drilled: April 30, 1984
Client:
EPA
Borehole depth: 106.5 ft
Location:
Kill Devil Hills, NC
Drilling method: Mud rotary
Project No.:
172
Sampling method: Split spoon
Geologist:
T. Corwin
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
60
26/40/
55
13
Very dense light gray fine sand
50(5")
65 -
29/50
(5")
75
14
Very dense light gray fine sand
70 —
50(6")
100
15
Very dense light gray medium sand
75 —
20/50
(5.5")
60
16
Very dense light gray medium to
coarse sand
80 —
29/50
(5")
80
17
Very dense light gray medium to
coarse sand
85 —
17/32/48
55
18
Very dense light gray medium to
coarse sand
6-91
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
90
11/46/
55
19
Very dense light gray fine sand
95 -
50(4")
Very dense light gray medium to
coarse sand
39/50
(3")
80
20
100 —
3/7/11
95
21
Silty fine sand to 100.5 ft, then
clayey silt to 101.0 ft, then silt
105 —
12/10/1C
100
22
Silty sand
See log for well K3A3 for sampling
from land surface to 55 ft
6-92
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: K3B1
Date well drilled: April 14, 1984
Client: EPA
Borehole depth: 9.0 ft
Location: Kill Devil Hills, NC
Drillinq method: Auqer
Pro.iect No.: 172
Samplinq method: Cuttinqs Examination
Geologist: J. Fish
Driller: A-C Borinqs, Inc.
Depth
Sampler
Percent
Sample
(feet)
Blows
Recovery
ID
Sample Description
0
Light brown fine to medium sand from
0 to 3 ft
5 -
Gray fine to medium sand from 3 to 9 ft
9 —
i
6-93
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
L/pll ID: K3C1
Date well drilled: April 14, 1984
Client: EPA
Borehole depth: 9.0 ft
Location: Kill Devil Hills. NC
Drillinq method: Auger
Projppt. Nn.: 172 ——
Samplinq method: Cuttings Examination
Geologist: Fish
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
5 —
Light brown fine to medium sand from
0 to 9 ft
9 —
6-94
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well__ID: K3D3 (ReDlaced with K3D3m
Client: EPA
Borehole deDth: 61.5 ft
Location: Kill Devil Hills, NC
Drillina mpthod: Mud rotarv
Project No.: 172
SamDlina method: SDlit sDOon
Geologist: T. Corwin
Driller: A-C Borinqs, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
Light brown fine to medium sand
at surface
5
2/2/3
100
2
Light brown fine to medium sand
10 -
5/5/6
15
3
Light brown fine to medium sand
15 -
1/2/2
60
4
Light brown fine to medium sand
to 15.9 ft, then sandy organic silt
20 -
8/15/24
Gray fine sand at 18 ft
60
5
Gray fine sand
25 -
15/16/22
55
6
Gray fine sand
6-95
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
30
16/19/1'
30
7
Gray fine to medium sand with a trace
35 —
of shell fragments
15/19/14
50
8
Gray fine to medium sand
40 -
16/26/35
60
9
Gray fine sand
45 -
20/32/41
55
10
Gray fine sand
50 —
17/50
(5.5")
30
11
Gray fine sand with some silt
55 -
34/50
(5")
50
12
Gray fine sand
60 —
17/43/5C
Not
Recorded
13
Gray fine sand with a trace of shell
fragments
6-96
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: K3D3B
Date well drilled: April 18, 1984
Client: EPA
Borehole depth: 86.5 ft
Location: Kill Devil Hills. NC
Drillinq method: Mud rotary
Project No.: 172
Samplinq method: Split spoon
Geologist: T. Corwin
Driller: A-C Borinqs, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
65
16/23/1£
15
14
Gray fine to medium sand with a trace
of shell fragments
70 -
19/43/
50(5")
65
15
Gray to tan medium sand
75 —
50(5.5")
20
16
Gray to tan medium sand with shell
fragments
80 —
29/17/16
0
' 17
No recovery
85 —
Clayey silt at 80.5 ft
3/4/5
Not
recorded
16
Gray fine sandy silt
See log for well K3D3 for sampling
from land surface to 60 ft
6-97
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: K3E1
Date well drilled: April 14, 1984
Client: EPA
Borehole depth: 10.0 ft
Location: Kill Devil Hills, NC
Drillinq method: Auger
Project No.: 172
Sampling method: Cuttings Examination
Geologist: J. Fish
Driller: A-C Borings. Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
t-* Ol o
o
1 1 1 1 1
Brown fine to medium sand from 0 to 6.5 ft
Gray fine to medium sand from 6.5 to 10 ft
6-98
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: K3F1
Date well drilled: April 14, 1984
Client: EPA
Borehole depth: 12.0 ft
Location: Kill Devil Hills. NC
Drilling method: Auger
Project No.: 172
Samplinq method: Cuttings Examination
Geologist: J. Fish
Driller: A-C Borings. Inc. .
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
Light brown fine to medium sand from
0 to 12 ft
5 —
10 -
12 __
6-99
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: K3G2
Date well drilled: April 12. 1984
Client: EPA
Borehole depth: 41.5 ft
Location: Kill Devil Hills. NC
Drilling method: Hollow stem auqer
Pro.iect No.: 172
Sampling method: Split spoon
Geologist: T. Corwin
Driller: A-C Borings. Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
3/3/4
40
1
Light brown fine sand
5 —
1/2/4
50
2
Light brown fine sand
10 —
1/2/6
40
3
Light gray fine to medium sand
15 -
7/11/16
45
4
Light gray fine sand
20 —
15/20/2t
45
5
Light gray fine sand
25 -
7/14/21
50
6
Light gray fine sand with shell
fragments
6-100
-------
LITHOLOGY SAMPLING RECORD Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
30
9/12/36
50
35 -
11/14/24 70
40 -
9/14/28
45
Light gray fine sand with shell fragments
Light gray fine with shell fragments
Light gray fine sand with shell fragments
6-101
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: K3G3
Date well drilled: April 13, 1984
Client: EPA
Borehole depth: 87.0 ft
Location: Kill Devil Hills, NC
Drilling method: Mud rotary
Project No.: 172
Sampling method: Split spoon
Geologist: J. Fish
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
45
27/50
0
10
No recovery
50 -
(5.5")
13/30/4C
60
11
Light gray fine sand
55 —
6/12/24
40
12
Gray and brown fine sand
60 —
10/37/
50(5")
60
13
Light brown fine to medium sand
65 —
25/50
(6")
75
14
Gray fine to medium sand with clayey
sand lenses
70 -
6/20/30
65
15
Gray fine sand with silty sand lenses
6-102
-------
LITH0L06Y SAMPLING RECORD
Page 2 of 2
Depth
Sampler
Percent
Sample
(feet)
Blows
Recovery
ID
Sample Description
75
8/13/14
20
16
Gray fine sand
80 -
5/6/8
30
17
Gray silty fine sand with a trace of clay
85 -
7/7/8
75
18
Gray clayey silt
See log for well K3G2 for sampling
from land surface to 40 ft
6-103
-------
LITHOLOGY SAMPLING RECORDS
FOR
ATLANTIC BEACH
6-105
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: A1A3
Date well drilled: June 20, 1984
Client: EPA
Borehole depth: 50.0 ft
Location: Atlantic Beach, NC
Drillinq method: Mud rotary
Pro.iect No.: 172
Samplinq method: Split spoon
Geologist: T. Corwin
Driller: A-C Borincs. Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
Tan fine to medium sand from 0 to 9 ft
5 —
10 -
Gray fine to medium sand from 9 to 20 ft
15 —
20 —
25 -
6-107
-------
LITHOLOGY SAMPLING RECORD Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
30
35 -
40 —
45 —
50 —
Pushed
sampler
100
Gray fine to medium sand with shells
from 20 to 39 ft
Silt from 39 to 40 ft
Gray fine to medium sand with shells
Soft gray clay from 46 to 50 ft
1
6-108
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: A1B3
Date well drilled: June 15. 1984
Client: EPA
Borehole depth: 42.0 ft
Location: Atlantic Beach. NC
Drillinq method: Mud rotary
Pro.iect No.: 172
SampHnq method: Split spoon
Geologist: J. Fish, T. Corwin
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
5 —
Tan fine sand with a trace of shells
from 0 to 12 ft
10 —
15 -
20 —
Gray silty fine sand from 12 to 24 ft
25 -
6-109
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 2
Depth
(feet)
30
35 —4
40 —
42 -
Sampler
Blows
Pushed
sampler
Percent
Recovery
30
Sample
ID
Sample Description
Tan to gray fine sand from 24 to 36 ft
Gray silty clay from 36 to 40 ft
Brown clay and shells from 40 to 40.5 ft,
then gray silty fine sand
6-110
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: A1C3
Date well drilled: June 19, 1984
Client: EPA
Borehole depth: 37.0 ft
Location: Atlantic Beach, NC
Drillinq method: Mud rotary
Pro.iect No.: 172
Samolinq method: Cu*+inqs examination
Geologist: T. Corwin
Driller: A-C Borinqs. Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
5 —
Tan fine to medium sand and shells
from 0 to 12 ft
10 —
15 -
Interbedded layers of fine sand and silty
fine sand with some shells from 12 to
24 ft
20 -
25 -
Gray fine sand and shells from
24 to 32 ft
6-111
-------
LITH0L06Y SAMPLING RECORD
Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
30
Gray silty fine sand from 32 to 37 ft
35 —
37 —
6-112
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: A1D2
Date well drilled: June 14, 1984
Client: EPA
Borehole depth: 52.0 ft
JLocation: Atlantic Beach, NC
Drill1nq method: Mud rotary
Project No.: 172
Sampling method: Split spoon
Geologist: J. F1sh
Driller: A-C Borings. Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
"6
Fine sand and gravel (probably fill)
from 0 to 7 ft
5 -
10 -
15 -
Gray fine sand from 7 to 18 ft
20 —
25 -
6-113
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
30
35 -
Gray fine sand with some shells
from 18 to 49 ft
40 —
45 -
50 -
No recovery. Wall of sampler has
a gray clay. Clay starts at 49 ft
Pushed
sampler
0
1
6-114
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: A1D3
Date well drilled: June 13, 1984
Client: EPA
Borehole depth: 110.0 ft
Location: Atlantic Beach, NC
Drillina method: Mud rotary
Pro.iect No.: 172
Samplinq method: Cuttings examination
Geologist: J. Fish
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
50
60 -
Gray fine sand with a trace of shells
from 52 to 70 ft
70 —
80 -
Tan fine sand and shells from 70 to 86 ft
90 —
Tan fine to coarse sand and shells from
86 to 96 ft
100 —
Very hard fine to coarse sand and shells
from 96 to 99 ft
110
Hard fine to coarse sand and shells from
99 to 110 ft
6-115
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
See log for well A1D2 for sampling
from land surface to 50 ft
6-116
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: A2A1
Date well drilled: June 1, 1984
Client: EPA
Borehole depth: 15.0 ft
Location: Atlantic Beach, NC
Drilling method: Auger
Project No.: 172
Cuttings and
Sampling method: Split spoon
Geologist: T. Corwin
Driller: A-C Borings. Inc.
Depth
Sampler
Percent
Sample
(feet)
Blows
Recovery
ID
Sample Description
0
Sampled
1
Brown to tan fine sand
5
cuttings
3/5/6
65
2
Tan to gray fine sand
6-117
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: A2A3
Date well drilled: June 1, 1984
Client: EPA
Borehole depth: 41.5 ft
Location: Atlantic Beach, NC
Drilling method: Mud rotary
Project No.: 172
Samplinq method: Split spoon
Geologist: J. Fish
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
10
9/21/17
40
3
Tan fine to coarse sand with shells from
15 -
10.0 to 10.5 ft, then tan fine sand from
10.5 to 11.5 ft
Silty fine sand starts at 14 ft
1/3/9
100
4
Gray fine sand and silty sand with
shel1s
20 —
18/40/
50(5")
75
5
Very dense gray fine sand
25 —
Dense gray fine sand with some shells
14/18/2;
55
6
30 -
Very dense gray fine sand with some shells
20/38/3'
30
7
35 —
Clay starts at 32.5 ft
1/1/2
90
8
Soft gray clay with a trace of silt and
sand
6-118
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
40
6/2/3
35
9
Loose gray fine sand from 40.0
to 40.5 ft. Probably gray clay
from 40.5 to 41.5 ft
6-119
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: A2A4
Date well drilled: June 14, 1984
Client: EPA
Borehole depth: 70.0 ft
Location: Atlantic Beach, NC
Drillinq method: Mud rotary
Pro.iect No.: 172
Sampling method: Cuttinqs examination
Geoloqist: J. F1sh |
Driller: A-C Borinqs, Inc.
Depth
(feet'
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
40
Gray clay from 41 to 58 ft
50 -
Gray clay with shells from 53
to 58 ft
60 —
70 —
Fine sand and shells from 58
to 70 ft
—
See well logs for wells A2A1 and A2A3
for sampling from land surface to 40 ft
"
6-120
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: A2B1
Date well drilled: June 1. 1984
Client: EPA
Borehole depth: 12.0 ft
Location: Atlantic Beach. NC
Drill1nq method: Auqer
.Project No.: 172
SamoHnq method: Split spoon
Geoloqlst: J. F1sh
Driller: A-C Borlnqs, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
5 -
2/4/5
100
Light brown fine sand
Light brown fine sand from 5.0 to
6.0 ft, then sllty fine sand from
6.0 to 6.5 ft
Sllty fine sand ends at 7.5 ft
2
6-121
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Uoll TD: A2B3
natP well drilled: June 1. 1984
m i pnt: EPA
Borehole depth: 37.0 ft
Location: Atlantic Beach. NC
Drilling method: Mud rotary
Sampling method: Split spoon
Geologist: J. Fish
Driller: A-C Borings. Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
10
7/11/9
45
3
Gray fine sand with a trace of shells
15 —
Very loose cray ne sand with some silt
2/1/1
90
4
20 -
Very dense gray fine sand
19/42/
50(5")
55
5
25 -
Very dense gray fine sand with shells
13/22/3?
70
6
30 —
Firm gray fine sand with shells
Clay starts at 32 ft
Firm gray silty clay with a trace of
shells
10/16/11]
35
7
35 -
2/3/3
55
8
6-122
-------
LITH0L06Y SAMPLING RECORD
Page 1 of 2
Well ID: A2B4
Date well drilled: May 31, 1984
Client: EPA
Borehole depth: 165.0 ft
Location: Atlantic Beach, NC
Drilling method: Mud rotary
Project No.: 172
Samplinq method: Split spoon
Geologist: T. Corwin
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
40
50 -
Interbedded gray silty clay, silt and
silty fine sand from 36.5 to 72 ft
60 -
70 -
80 —
Greenish-gray fine to coarse sand and
shells from 72 to 110 ft
90 —
6-123
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
100
110 —
Green silty fine sand
Pushed
100
9
120 —
sampler
130 —
Green silty fine sand from
110 to 164 ft
140 —
150 —
160 —
Limestone from 164 to 165 ft
165 -
See logs for wells A2B1 and A2B3 for
sampling above 40 ft
6-124
-------
LITH0L06Y SAMPLING RECORD
Page 1 of 1
Well ID: A2C1
Date well drilled: June 1, 1984
Client: EPA
Borehole depth: 13.0 ft
Location: Atlantic Beach. NC
DrillInq method: Auqer
Pro.lect No.: 172
SampHnq method: Split spoon
Geologist: T. Corwin
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
5 —
1/6/5
100
2
Light brown fine sand to 2 ft,
then gray fine sand to 5 ft
Tan to gray fine to medium sand
6-125
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: A2C3
Date well drilled: May 24, 1984
Client: EPA
Borehole depth: 31.5 ft
Location: Atlantic Beach, NC
Drillinq method: Mud rotary
Pro.iect No.: 172
Samplinq method: Split spoon
Geologist: T. Corwin
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
10
2/1/1
40
3
Very loose gray fine sand
15 -
14/16/16
50
4
Dense gray fine sand
20 —
13/16/22
35
5
Dense gray fine sand with a trace
of shells
25 -
Clayey silt starts at 23 ft
1/4/12
100
6
Soft gray clayey silt from 25.0 to
25.7 ft, then firm gray silty fine
30 —
sand from 25.7 to 26.5 ft
2/1/1
100
7
Loose gray^silty fine sand from 30.0
to 31.2 ft, then soft gray clayey silt
from 31.2 to 31.5 ft
6-126
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: A2C4
Date well drilled: June 6, 1984
Client: EPA
Borehole depth: 75.0 ft
Location: Atlantic Beach, NC
Drilling method: Mud rotary
Project No.: 172
Sampling method: Split spoon
Geoloqist: T. Corwin
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
30
Soft gray clayey silt and gray silty
fine sand from 31.5 to 40 ft
35 —
40 -
Soft gray clay
Pushed
sampler
100
8
45 —
50 -
Clayey silt and silty sand from
41.5 to 60 ft
55 -
6-127
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
60
65 —
Gray fine to medium sand and
shells from 60 to 75 ft
70 —
75 -
See logs for wells A2C1 and A2C3 for
sampling from land surface to 30 ft
6-128
-------
LITHOLOGY SAMPLING RECORDS
FOR
PINE KNOLL SHORES
6-129
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LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: P1A2
Date well drilled: June 4, 1984
Client: EPA
Borehole depth: 45.0 ft
Location: Pine Knoll Shores, NC
Drillinq method: Mud rotary
Project No.: 172
Samplinq method: Cuttinqs
Geologist: J. Fish
Driller: A-C Borinqs, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
Sampled
1
Tan sand and crushed limestone
cuttings
(Fill material)
5 —
Sampled
cuttings
2
Tan fine sand
6-131
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LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: P1A3
Date well drilled: June 4, 1984
Client: EPA
Borehole depth: 66.5 ft
Location: Pine Knoll Shores, NC
Drillinq method: Mud rotary
Project No.: 172
Sampling method: Split sooon
Geologist: T. Corwin
Driller: A-C Borlnas. Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
10
6/8/8
35
3
Firm tan fine to medium sand
Tan fine sand ends at 12.0 ft
15 —
21/41/
50(4")
55
4
Very dense light gray fine to medium
sand with shells
20 -
23/47/
50(4")
75
5
Very dense light gray fine to medium
sand with shells
25 -
27/50
(5")
75
6
Very dense light gray fine to medium sand
with shells
30 -
18/29/34
60
7
Very dense light gray fine sand with some
shel1s
35 -
12/16/1S
60
8
Dense gray fine sand with a trace of
shel1s
6-132
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LITH0L06Y SAMPLING RECORD
Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
40
11/24/
70
9
Very dense gray fine to medium sand
45 —
50(5")
15/41/
50(4")
65
10
Very dense gray fine sand
50 —
33/50
(4")
100
11
Very dense gray fine sand
55 -
Very dense gray fine sand
33/50
(4")
80
12 '
60 -
Very dense gray fine sand with
a trace of shells
23/50
(6")
65
13
65 —
3/4/4
100
14
Gray clay with some fine sand
See log for well P1A2 for sampling
from land surface to 5 ft
6-133
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LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: P1B1
Date well drilled: May 26, 1984
Client: EPA
Borehole depth: 19.0 ft
Location: Pine Knoll Shores. NC
Drilling method: Auger
Project No.: 172
Sampling method: Cuttings Examination
Geologist: J. Fish
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
Light brown fine sand from 0 to 2 ft
5 —
Tan fine sand with some shells from
2 to 16 ft
10 —
15 —
Tan to gray fine to medium sand with
some shells from 16 to 17 ft
19 —
Tan fine sand with some shells from
17 to 19 ft
6-134
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LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: P1C1
Date well drilled: May 27, 1984
Client: EPA
Borehole depth: 13.0 ft
Location: Pine Knoll Shores, NC
Drillinq method: Auqer
Pro.iect No.: 172
Samplinq method: Split spoon
Geoloqist: J. Fish
Driller: A-C Borinqs, Inc.
Depth
(feet)
Sampler
B1 ows
Percent
Recovery
Sample
ID
Sample Description
0
Pushed
100
1
Tan to dark brown fine sand
5
sampler
2/4/6
100
2
Dark brown fine sand with lenses
of organic silt
10 -
1/5/4
100
3
Gray to green fine sand with lenses of
organic silt
6-135
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LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: P1C3
Date well drilled: May 22, 1984
Client: EPA
Borehole depth: 66.5 ft
Location: Pine Knoll Shores, NC
Drilling method: Mud rotary
Project No.: 172
Samplinq method: Split spoon
Geologist: T. Corwin
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
11 —
1
100
3A
Tan fine sand and silt
15 —
12/21/24
60
4
Dense light gray fine sand
20 —
15/23/2$!
60
5
Dense gray fine to medium sand with
some shells
12/18/26
25
100
6
Firm to dense gray fine to medium sand
30 -
8/12/1*
70
7
Dense gray fine sand with a trace of silt
35 -
14/34/5C
80
8
Very dense fine to medium sand with shells
6-136
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LITHOLOGY SAMPLING RECORD
Page 2 of 2
Depth
(feet)
Sampler
Blows
3ercent
Recovery
Sample
ID
Sample Description
40
13/25/3E
50
9
Very dense gray fine sand
45 —
19/44/
50(5")
60
10
Very dense light gray fine sand with
some shells
50 -
Dense gray medium sand with shells
20/12/26
80
11
55 -
Very dense gray medium sand with shells
Clay starts at 58 ft
10/19/4C
80
12
i
60 —
Soft gray interbedded clay, silt, and
silty fine sand
1/6/6
90
13
65 —
Pushed
sampler
65
14
No recovery. Trace amount of clay on
spoon
6-137
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LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: P1C4
Date well drilled: June 12, 1984
Client: EPA
Borehole depth: 79.0 ft
Location: Pine Knoll Shores, NC
Drillinq method: Mud rotary
^Project No.: 172
Samplinq method: Cuttings Examination
Geologist: T. Corwin, J. Fish
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
70
Fine to medium sand from 69 to 73 ft
75 -
Green silt and fine sand from 73 to 79 ft
79 —
See logs for wells P1C1 and P1C3 for
sampling from land surface to 65 ft
6-138
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LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: P1D1
Date well drilled: May 26, 1984
Client: EPA
Borehole depth: 15.0 ft
Location: Pine Knoll Shores. NC
Drilling method: Auger
Project No.: 172
Sampling method: Cuttinqs Examination
.Geologist: J. Fish
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
Dark brown fine sand from 0 to 6 ft
5 —
Dark brown organic silt from 6
to 6.5 ft
10 —
Light brown fine sand with shells
from 6.5 to 15 ft
15 -
6-139
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LITHOLOGY SAMPLING RECORD
Page 1 of 1
WpII TP* P1E2
Date well drilled: May 26, 1984
Client*
Borehole deDth: 35.0 ft
1 oration: Pine Knoll Shores. NC
Drillinq method: Mud rotary
Proiect No»: 172
SamDlina method: Split spoon
Geologist: J. Fish
Driller: A-C Borings. Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
Pushed
60
1
Light brown fine sand from 0 to 0.6 ft,
then gray fine sand from 0.6 to 1.5 ft
Brown fine sand
sampler
5 —
Pushed
sampler
45
2
6-140
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: P1E3
Date well drilled: May 25, 1984
Client: EPA
Borehole depth: 61.5 ft
Location: Pine Knoll Shores, NC
Drillinq method: Mud rotary
Pro.iect No.: 172
Samplinq method: Split spoon
Geologist: T. Corwln
Driller: A-C Borinqs, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
10
3/6/7
45
3
Tan fine sand
15 —
Gray fine sand probably starts at 12 ft
13/27/35
80
4
Dense gray fine sand
20 —
Dense gray fine sand with shells
18/27/3-
80
5
25 -
Dense gray fine sand with shells
10/21/25
80
6
30 -
Dense gray medium sand with shells
20/32/32
65
7
35 -
Medium sand and shells from 35.0 to 35.2
ft, then dense gray sand from 35.2
¦724/
50(5")
80
8
to 36.5 ft
6
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
40
23/47/
70
9
Very dense gray fine to medium sand
45 -
50(5")
with shells
50(5")
85
10
Very dense gray medium sand with shells
50 —
20/24/
50(5")
50
11
Very dense fine to medium gray sand
with some shells
55 -n
17/25/31
55
12
Dense gray medium sand with shells
Silt at 57 ft
60 —
Pushed
sampler
100
13
Soft interbedded gray clay, clayey silt
and silty sand
See log for well P1E2 for sampling
from land surface to 5 ft
6-142
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LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: P2A1
Date well drilled: June 6, 1984
Client: EPA
Borehole depth: 20.0 ft
Location: Pine Knoll Shores, NC
Drillinq method: Auqer
Project No.: 172
Samplinq method: Cutt.inqs
Geologist: T. Corwin
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
5 -
Sampled
cuttings
Sampled
cuttings
1
Tan fine to medium sand
Light brown to tan fine to medium sand
with some shells
2
6-143
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: P2A3
Date well drilled: June 5. 1984
Client: EPA
Borehole depth: 67.0 ft
Location: Pine Knoll Shores, NC
Drillinq method: Mud rotary
Project No.: 172
Samplinq method: Split spoon
Geologist: J. Fish, T. Corwin
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
10
6/10/13
55
3
Tan to light brown fine to medium sand
15 -
with some shells
4/8/16
65
4
Firm tan to light brown fine to medium
sand with some shells
20 -
23/50
100
5
Very dense tan to light brown fine to
medium sand with some shells
25 —
35/50
(5")
90
6
Very dense tan to light brown fine to
medium sand with some shells
30 -
22/31/
50(5")
70
7
Dense tan to gray medium sand with shells
from 30 to 30.2 ft, then dense gray fine
sand from 30.2 +o 31.5 ft
35 —
19/15/2*
65
8
Dense gray fine sand with shells
6-144
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
40
11/17/2-
80
9
Dense gray fine sand with a trace of
shells
45 —
12/20/2?
55
10
Dense gray fine sand with a trace of
shel1s
50 —
12/23/3E
50
11
Very dense fine sand with a trace of
shells
55 -
22/35/
50(4")
70
12
Very dense gray fine sand with a trace
of shells
60 -
21/24/3C
60
13
Dense gray fine sand with a trace of
shelIs
65 —
Pushed
sampler
100
14
Soft gray clayey and silty fine sand
See log for well P2A1 for sampling
from land surface to 5 ft
6-145
-------
LITHOLOGY SAMPLING RECORD Page 1 of 1
Well ID: P2B1
Date well drilled: May 27, 1984
Client: EPA
Borehole depth: 16.5 ft
Location: Pine Knoll Shores, NC
Drillinq method: Auqer
Project No.: 172
Samplinq method: Cuttinqs Examination
Geologist: 0. Fish
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
5 —¦
Tan to light brown fine sand from
0 to 12 ft
10
15 -
16.5 —f
Gray fine to medium sand with a
trace of shells from 12 to 16.5 ft
6-146
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: P2C3
Date well drilled: May 23, 1984
Client: EPA
Borehole depth: 51.5 ft
Location: Pine Knoll Shores, NC
Drillinq method: Mud rotary
Project No.: 172
Samplina method: Split spoon
Geoloaist: J. Fish
Driller: A-C Borinqs, Inc.
Depth
(feet)
Sampler
B1 ows
Percent
Recovery
Sample
ID
Sample Description
0
Pushed
25
1
Light to dark brown fine sand with
sampler
some organic silt
5 —
10 -
No sample
1/3/4
50
3
Dark brown fine sand and organic silt
15 —
Dense gray fine to medium sand
17/20/2-
40
4
20 —
Dense gray fine sand
13/21/2^
60
5
25 -
11/20/25
65
6
Dense gray fine sand
6-147
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
30
17/23/41
65
7
Very dense gray fine sand with a trace
35 -
of shel1s
Firm gray fine sand
6/7/12
100
8
40 -
Stiff gray fine sandy silt from 40 to 40.5
ft, then gray fine sand from 40.5 to 41.5
5/6/4
80
9
45 -
ft
1/1/1
40
id
Very soft gray clay
50 -
Very soft gray clay
1/1/1
100
11
6-148
-------
LITH0L06Y SAMPLING RECORD
Page 1 of 1
Well ID: P2C4
Date well drilled: June 11. 1984
Client: EPA
Borehole depth: 75.0 ft
Location: Pine Knoll Shores, NC
Drill1nq method: Mud rotary
Pro.iect No.: 172
Sampling method: Split spoon
_Geologist: T. Corwin
Driller: A-C Borinqs, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
50
Firm gray sllty fine sand with shells
from 51.5 to 65 ft
55 -
60 —
65 —
Firm gray silty fine sand with shells
Pushed
sampler
20
12
70 —
Firm gray sllty fine sand with shells
from 66.5 to 75 ft
75 -
See log for well P2C3 for sampling
from land surface to 55 ft
6-149
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: P2D1
Date well drilled: June 2. 1984
Client: EPA
Borehole depth: 15.0 ft
Location: Pine Knoll Shores, NC
Drillinq method: Auqer
Project No.: 172
Samplinq method: Cuttinqs Examination
Geoloqist: T. Corwfn
Driller: A-C Borinqs, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
Light brown fine sand from 0 to 7.5 ft
5 -
10 —
Light brown fine sand with a trace of
silt from 7.5 to 15 ft
15 —
—
.
6-150
-------
L1TH0L0GY SAMPLING RECORD
Page 1 of 1
Well ID: P2E1
Date well drilled: June 2. 1984
Client: EPA
Borehole depth: 15.0 ft
Location: Pine Knoll Shores, NC
Drillinq method: Auqer
Project No.: 172
Cuttings and
Samplinq method: Split spoon
Geologist: T. Corwin
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
Sampled
cuttings
1
Black loainy silt
5
Pushed
sampler
100
2
Brown silty sand from 5 to 5.5 ft,
then brown peat from 5.5 to 6.5 ft
6-X51
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: P2E3
Date well drilled: June 2, 1984
Client: EPA
Borehole depth: 51.5 ft
Location: Pine Knoll Shores, NC
Drillinq method: Mud rotary
Project No.: 172
Samplinq method: Split spoon
Geologist: T. Corwin
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
10
9/12/8
40
3
Firm tan to light gray fine sand with a
15 —
trace of silt
1/2/5
85
4
Loose tan to light gray fine sand with
a trace of silt
20 —
13/24/29
70
5
Dense gray fine to medium sand with shells
25 —
19/34/31
85
6
Very dense gray fine to medium sand with
shells
30 —
11/19/2-
80
7
Dense gray fine to medium sand with shells
35 —
17/23/2*
30
8
Dense gray fine to medium sand with shells
6-152
-------
LITHOLOGY SAMPLING RECORD
Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
40
8/41/
85
9
Very dense gray fine sand
50(5")
45 —
1/3/2
90
10
Loose gray silty fine sand
50 -
Pushed
sampler
100
11
Soft gray clay
See log for well P2E1 for sampling
from land surface to 5 ft
6-153
-------
LITHOLOGY SAMPLING RECORDS
FOR
SURF CITY
6-155
-------
LITHOLOGY SAMPLING RECORD Page 1 of 1
Well ID: S1A1
Date well drilled: June 28, 1984
Client: EPA
Borehole depth: 15.0 ft
Location: Surf City, NC
DrilUnq method; Auqer
Project No.: 172
SamDlinq method: Mash cuttlnqs
Geologist: T. Corwln
Driller: A-C Borinqs. Inc.
Depth
[feet)
Sampler
Blows
'ercent Sample
Recovery I ID
Sample Description
Sampled
cuttings
Tan fine sand
6-157
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: S1A2A (Abandoned)
Date well drilled: July 31. 1984 1
Client: EPA
Borehole depth: 11.5 ft f
Location: Surf Citv. NC
f
Drilling method: Auqer
Project No.: 172
Samplinq method: Split spoon
Geologist: J. Fish
Driller: A-C Borings. Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
5 -4
6/7/7
10 -4
2/4/6
100
100
Tan fine to medium sand with some shells
White fine to medium sand with some shells
6-158
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: S1A2
Date well drilled: July 5, 1984
Client: EPA
Borehole depth: 41 ft
Location: Surf City, NC
Drilling method: Mud rotary
Project No.: 172
Sampling method: Split spoon
Geologist: J. F1sh
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
15
4/8/11
50
4
Firm white and brown fine to coarse sand
and shells
20 -
15/24/25
60
5
Very dense tan fine to coarse sand with
some shells
25 -
19/33/3?
70
6
Very dense tan fine to medium sand with
some shells
30 -
15/18/lSj
100
7
Very dense tan fine to medium sand with
a trace of shells
35 —
17/16/8
30
8
Firm gray fine sand with some shells
40 —
24/50
(6")
100
9
Very dense gray fine sand from 40.0 to
40.5 ft, then gray fossilIferous lime-
stone
6-159
-------
LITH0L06Y SAMPLING RECORD
Page 1 of 1
Well ID: S1A3
Date well drilled: July 24, 1984
Client: EPA
Borehole depth: 60.0 ft
Location: Surf City, NC
Drilling method: Mud rotary
Project No.: 172
Sampling method: Cuttings examination
Geologist: J. Fish
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
45
Gray limestone from 41.5 to 50 ft
50 —
55 —
Tan sandstone from 50 to 60 ft
60 —
See logssfor wells S1A1, S1A2A and
S1A2 for sampling from land surface
to 40 ft
6-160
-------
LITHOLOGY SAMPLING RECORD Page 1 0f 1
Well ID: S1B1
Date well drilled: June 28, 1984
Client: EPA
Borehole depth: 16.0 ft
Location: Surf City, NC
Drilling method: Auger
Pro.iect No.: 172
Sampling method: Wash cuttings
Geologist: T. Corwin
Driller: A-C Borings. Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
5 —1
Sampled
cuttings!
Sampled
cuttings!
Brown fine to medium sand and shells
Brown fine to medium sand and shells
6-161
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: S1B2
Date well drilled: June 29, 1984
Client: EPA
Borehole depth: 33.0 ft
Location: Surf City, NC
Drillinq method: Mud rotary
Project No.: 172
Samplinq method: Split spoon
Geologist: J. Fish
Driller: A-C Borinqs, Inc.
Depth
(feet)
Sampler
B1 ows
Percent
Recovery
Sample
ID
Sample Description
10
8/9/9
"50
3
Firm brown medium sand and shells
15 —
6/10/16
45
4
Firm gray and brown coarse sand and shells
20 -
4/6/8
40
5
Firm gray coarse sand and shells
25 -
12/14/13
50
6
Dense gray medium sand
30 -
14/24/2J
40
7
Dense light gray fine sand
6-162
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
_Well ID: S1B3
Date well drilled: July 24, 1984
Client: EPA
Borehole depth: 70.0 ft
Location: Surf City. NC
Drillinq method: Mud rotary
Project No.: 172
SampHnq method: Cuttinqs examination
Geologist: T. Corwin
Driller: A-C Borings. Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
30
Dark gray fine sandy silt from 33 to 36 ft
40 —
Light gray limestone from 36 to 53 ft
50 -
60 —
Tan sandstone from 53 to 70 ft
70 -
See logs for wells S1B1 and S1B2 and
for sampling from land surface to 30 ft
6-163
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: S3A1
Date well drilled: June 28. 1984
.Client: EPA
Borehole deoth* 20.0 ft
Location: Surf C1tv. NC
DrillIna method: Auoer
Project No.: 172
Samollna method: Wash cuttlnas
Geologist: T. Corwln
Driller: A-C Borfnas. Inc.
Depth
•(feet)
Sampler
'Blows
Percent
Recovery
Sample
ID
i
Sample Description
0
\
5 —
Sampled
cutting:
Tan fine to medium sand with some shells
Sampled
z
Tan to brown fine to medium sand with some
cutting!
'
shells
—
6-164
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LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID:
S3A2
Date well drilled: July 9. 1984
Client:
EPA
Borehole death: 34.0 ft
Location:
Surf C1t.v. NC
Protect No.:
172
Geologist:
J. F1sh. T. Corwln
Driller: A-C Borings. Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
10
7/5/6
20
3
Firm gray and brown fine to medium
sand with a trace of shells
15 -
7/11/13
35
4
Firm gray fine to coarse sand with
some shells
20 -
7/8/11
30
S
Firm gray fine to coarse sand with
some shells
25 -
14/17/24
"55
6
Dense tan medium to coarse sand and shells
30 -
7/8/8
50
7
Firm tan medium to coarse sand and shells
6-165
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: S3A3
Date well drilled: July 18, 1984
Client: EPA
Borehole depth: 70.0 ft
Location: Surf City. NC
Drillinq method: Mud rotary
Project No.: 172
Samplinq method: Cuttinqs examination
Geoloqist: T. Corwin
Driller: A-C Borinqs, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
30
Dark gray fine sandy silt from
33 to 38 ft
40 -
Light gray limestone from 38 to 56 ft
50 —
Interbedded limestone and very fine
sand from 56 to 65 ft
60 —
Interbedded limestone and very fine
sand from 65 to 70 ft
70 —
—
See logs for wells S3A1 and S3A2 for
sampling from land surface to 30 ft
6-166
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: S3B1
Date well drilled: July i^9^4
Client: EPA
Borehole deDth: 18.0 ft
Location: Surf City, NC
Drlllina method: Mud rotary
Project No.: 172
Sampi 1 nq method: Cuttw nntlnn
Geologist: T. Corwin
Driller: a-C Borings. Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
0
5 -
10 —
T«n t0 radium sand with some
shells from 0 to 6 ft
Gray,fine to medium sand with some
shells from 6 to 10 ft
6-167
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: S3B3
Date well drilled: .inn» -|9^4
Client: EPA
Borehole deDth: 52.0 ft
Location: Surf City, NC
Drilling method: MuH rotary
Project No.: 172
Sampling method: Split SDoon
Geologist: J. Fish, T. Corwin
Driller: A-C Borings, Inc.
Depth
(feeti
Sampler
(Blows)
Percent
Recovery
Sample
ID
Sample Description
10
15/21/2
50
3
Dense gray fine to medium sand with
15 -
some shells
10/15/1f
50
4
Dense gray fine to medium sand with
some shells
20 —
17/30/32
55
5
Shells from 20.0 to 20.4 ft, then
very dense gray fine to medium sand
from 20.4 to 21.5 ft
25 -
14/19/2?
60
6
Shells from 25.0 to 25.6 ft, then light
gray fine to medium sand from 25.6 to
26.5 ft
30 -
16/16/1'
20
7
Dense light gray fine to medium sand
Silty clay encountered from 31 to 34 ft,
then limestone
35 -
50(5.5";
90
8
Light gray limestone
6-168
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 2
Well ID: S3B4
Date well drilled: July 4, 1984
Client: EPA
Borehole depth: 135.0 ft
Location: Surf City. NC
Drilling method: Mud rotary
Project No.: 172
Sampling method: Cuttinas examination
Geologist: T. Corwin
Driller: A-C Borings. Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
40
Light gray limestone from 34 to 60 ft
50 -
60 -
70 -
Interbedded gray limestone and green
sandstone from 60 to 75 ft
80 -
90 -
Green sandstone from 75 to 113 ft
6-169
-------
lithology sampling record
Page 2 of 2
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sampl e
ID
Sample Description
100
110 -
120 —
130 —
135 —
Gray limestone from 113 to 135 ft
See logs for wells S3B1 and S3B3 for
sampling from land surface to 40 ft
6-170
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: S3C1
Date well drilled: June 28, 1984
Client: EPA
Borehole depth: 16.0 ft
Location: Surf City, NC
Drilling method: Auger
Pro.iect No.: 172
Sampling method: Wash cuttings
Geologist: T. Corwin
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows,
Percent
Recovery
Sample
ID
Sample Description
0
Black organic silt
Sampled
cutti ngs
i
5 -
Sampled
Gray silty fine to medium sand
cuttings
2
6-171
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: S3C2
Date well drilled: July 6. 1984
Client: EPA
Borehole deDth: 30.0 ft
Location: Surf City» NC
DrllUna method: Mud rotary
SamDlinq method: Sollt spoon
Geologist: T. Corwin. J. Fish
Driller: A-C Borings, Inc.
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
10
13/12/H
90
3
Firm gray fine to medium sand with
15 -
some shells
Firm gray fine to medium sand with
some shells
5/7/11
55
4
20 -
Dense gray fine to medium sand with
some shells
20/22/2(
50
5
25 -
Firm gray fine sand
3/8/10
65
6
30 -
Gray silty clay from 27 to 30 ft
6-172
-------
LITHOLOGY SAMPLING RECORD
Page 1 of 1
Well ID: S3C3
Date well drilled: July 17, 1984
Client: EPA
Borehole depth: 80.0 ft
Location: Surf C1t.y, NC
Drilling method: Mud rotary
Project No.: 172
Sampling method: Cuttings examination
Geologist: T. Corwln
Driller: A-C Borings. Inc.
'
Depth
(feet)
Sampler
Blows
Percent
Recovery
Sample
ID
Sample Description
30
Light gray limestone from 30 to 43 ft
40 -
Tan sandstone from 43 to 48 ft
50 -
60 -
Interbedded sandstone and limestone
from 48 to 70 ft
70 -
Green partially consolidated sand and
sandstone from 70 to 80 ft
80 -
See logs for wells S3C1 and S3C2 for
sampling from land surface to 30 ft
6-173
-------
APPENDIX C
6-175
-------
SECTION 1
AQUIFER PUMPING TEST
AT
KILL DEVIL HILLS
6-177
-------
AQUIFER PUMPING TESTS
One aquifer pumping test was conducted in each of the three study
areas. Eight-hour tests were conducted in Kill Devil Hills and Pine
Knoll Shores. A four-hour test was conducted in Surf City. These tests
are described in the sections that follow.
The pumping rate to be used for each of the tests was determined
prior to testing. The pumping capacity of each test well was determined
by pumping the well at various rates while observing drawdowns in the
well. This information was used to determine a pumping rate for testing
that would assure that the well would produce the maximum amount of water
possible without creating excessive drawdowns in the well. This prelimi-
nary testing was done the day before conducting the aquifer pumping test.
6-178
-------
AQUIFER PUMPING TEST AT KILL DEVIL HILLS, NC
An 8-hour aquifer pumping test was performed on 16 May 1984 in Kill
Devil Hills, NC. Pumping began at 0700 Eastern Daylight Time (EDT) and
lasted until 1510 EDT. Well K3D2 was the pumped well. The average
pumping rate from the well was 28.5 gallons per minute (gpm). The pumped
water was discharged to the ground surface approximately 260 feet south
of the well. Wells K3D1 and K3D3 were used as observation wells.
Well construction details for the pumped well and the observation
wells varied between wells. Well K3D1 is completed in unconsolidated
sand deposits near the water table surface. There is a one to two foot
thick layer of peat material that starts about four feet below the base
of this well. Well K3D3 is completed in unconsolidated sand deposits
near the top of a clayey sand that is approximately 77 feet below the
water table. Well K3D2 is completed in unconsolidated sand deposits be-
tween the clayey sand and the peat material. Construction details for
the wells are summarized in Table 1. A cross section showing the litho-
logy at the site and the spacial relationship between wells is yiven in
Figure 1.
Water levels were measured in the pumped well and each of the
observation wells. Water level declines were observed in the pumped well
and in observation well K3D3. The water level in observation well K3D1
remained approximately constant during the pumping period. The observed
water levels and computed water level changes during pumping are pre-
sented at the end of this section.
The computed transmissivity and hydraulic conductivity for the
unconsolidated deposits are 10,900 gallons per day per foot (gpd/ft) and
545 gallons per day per foot squared (gpd/ft2). The effective aquifer
thickness used for the hydraulic conductivity computation was 20 feet,
which is the length of the screened interval in the pumped well. The
behavior of water levels in observation wells K3D1 and K3D3 during
testing indicated that most of the water being extracted from these depo-
sits in the pumping well vicinity was probably the result of horizontal
flow to the well within the area of the screened interval. Layering of
the sands and shells in the aquifer promotes the horizontal flow of water
while minimizing the vertical flow.
The modified Theis nonequilibrium analysis (Ferris et. al., 1962)
and the Theis recovery analysis (Ferris et al., 1962), together with
water level data for the pumped well, were used to compute the
transmissivity of the unconsolidated deposits. Hydraulic conductivity
for these deposits was estimated based on the computed transmissivity and
estimated effective saturated thickness in the vicinity of the well.
The aquifer pumping test analysis is presented at the end of this
section.
The data collected at observation well K3D3 were not used for
determining the hydraulic properties of the unconsolidated deposits. A
preliminary analysis using the water level data from this well indicated
that the drawdowns in this well were strongly influenced by the partial
penetration of the pumping well.
6-179
-------
TABLE 1
WELL CONSTRUCTION SUMMARY
Well Well Well Top of open Screen
number depth diameter interval below length
(feet) (Inches) land surface (feet)
(feet)
K3D1 13.0 6 8.0 5.0
K3D2 46.5 4 26.5 20.0
K3D3 79.0 2 74.0 5.0
6-180
-------
11.8'
20'i
-80'-
\+— 5.3'-H
.and Surface
r20'
V
8EA LEVEL —
i
] K3D1
8and
-20-
K3D2
Sand
J
0
1
1
0)
o
r
I
| K3D3
— SEA LEVEL
Paat
20'
—40'
—60'
—80'
__| EXPLANATION
10 FEET
K3D1
Scraan
V
A
Wall uaad (or aqullar pumping
taat and wall numbar
Watar Tabla
Figure 1. Geologic cross-section in vicinity of aquifer pump test
site at Kill Devil Hills, N.C.
6-181
-------
The data collected at observation well K3D1 indicates that the
unconsolidated deposits that lie below the peat layer are hydraulically
separated from those that lie above this layer. The water level in this
observation well did not change significantly during the pumping period.
This well is completed in the unconsolidated deposits above the peat
layer. The water level data collected at this well, although qualitati-
vely informative, could not be used for any type of quantitative analy-
ses.
REFERENCES
Ferris, J.B. et al. 1962. Theory of aquifer tests: United States
Geological Survey Water Supply Paper 1536-E.
6-182
-------
WATER LEVELS FOR AQUIFER PUMPING TEST
Water levels were recorded for the pumped well (Well K3D2) and for
wells K3D1 and K3D3. These data are tabulated for each well in the
tables which follow. In these tables, the column headings have the
following meaning:
Date: Date of reading.
Time: Time of reading, Eastern Daylight Time
(EDT).
Depth to water: The depth to water below the measuring
point, in feet.
Flow meter reading: The total gallons of water recorded by
(pumped well only) the flow meter. The meter reading was
339752.5 gallons prior to beginning the
test.
Remarks: Any pertinent remarks.
6-183
-------
TABLE A1
WATER LEVEL AND PUMPING DATA FOR HELL K3D2
Date
(198*)
Time
(EDT)
Depth to
water
(feet)
Flow meter
reading
(oallons)
Remarks
May 16
0625
0658
0700
0700s10
0700:30
0701
0702
0703
070^*15
0705
0706
0707
0708
0709
0710:05
0711:15
0712
0713
071*
0715
0716:38
0718
0718:15
0719:38
0720
0721
0723
0728
0730
073*
0736
0738
07*0
07*3
07*7
0750
0751
0755
0756
0800
0803
0811
0820
0826
0830
0831
08*0
0850
0855
0900
0913
0915
0927
0930
09*5
09*6
1000
1016
1020
1021
5.85
5.85
12.00
1*.10
1*.59
15.00
15.53
15.65
15.79
15.79
15.97
15.91
15.96
16.02
15.9*
15.89
15.91
16.18
16.10
16.06
15.93
16.0*
16.30
16.29
16.31
16.35
16.38
16.39
16.*0
16.*3
16.*3
16.37
16.3*
16.39
16.39
16.38
16.*7
16.*5
16~52
16.58
16.60
16.83
16.79
16.88
16.87
17.1*
17.17
339752.5
3399236.5
3*0091*.2
3*02631.0
Pump on
Measure 28.7 gpm using flow meter
Measire 29.0 gpm using flow meter
Adjust pump
Measure 28.3 gpm using flow meter
Adjust pump
Measure 27.9 gpm using flow meter
Adjust pump
Measure 28.7 gpm using flow meter
Adjust pump
Measure 27.9 gpm using flow meter
Adjust pump
Measure 28.0 gpm using flow meter
Adjust pump
Measure 28.8 gpm using flow meter
Measure
Measure
Measure
Measure
Measure
Measure
Measure
28.* gpm using
28.* gpm using
28.3 gpm using
28.6 gpm using
28.2 gpm using
28A) gpm using
28.3 gpm using
flow meter
flow meter
flow meter
flow meter
flow meter
flow meter
flow meter
Measure 28.2 gpm using flow meter
Measure 28.6 gpm using flow meter
Measure 28.* gpm using flow meter
Measure 28.8 gpm using flow meter
Measure 29.3 gpm using flow meter
6-1^
-------
TABLE A1
(continued)
WATER LEVEL AND PUMPING DATA FOR WELL K3D2
Date
(1984)
Time
(EOT)
Depth to
water
(feet)
Flow meter
reading
(gallons)
Remarks
May 16
(continued)
1030
1045
1052
1100
1110
1115
1130
1146
1149
1200
1215
1230
1245
1251
1300
1315
1330
1344
1345
1400
1404
1415
1430
1445
1500
1510
1510:06
1510 ;38
1511
1512:30
1513:40
1514
1515
1516
1517
1518
1519
1520
1522
1524
1527
1530
1534
1537
1540
1545
1552
1556
1600
1610
1626
1703
1730
17.10
17.23
17.17
16.93
16.87
17.11
17.01
17.01
17.00
17.03
17.04
17.01
17.04
17.02
17.02
17.02
17.05
17.08
17.00
1!:88
7.68
7.31
7.18
7.13
7.07
7.02
6.95
6.91
6.87
6.83
6.79
6.73
6.69
6.63
6.57
6.55
6.51
6.47
6.42
6.40
6.36
6.32
6.25
6.15
6.12
3404375.0
3404659.0
3406090.0
3407801.0
3409505.0
3411209.0
3411492.4
Measure 29.3 gpm using flow meter
Measure 29.3 gpm using flow meter
Measure 28.6 gpm using flow meter
Measure 29.0 gpm using flow meter
Measure 28.6 gpm using flow meter
Measure 28.4 gpm using flow meter
Measure 28.4 gpm using flow meter
Measure 28.4 gpm using flow meter
Measure 28.4 gpm using flow meter
Measure 28.4 gpm using flow meter
Measure 28.4 gpm using flow meter
Pump off
Total gallons pumped Is 13,963.9 gallons
Average pumping rate Is 28.5 gpm
6-185
-------
TABLE A2
WATER LEVEL DATA FOR OBSERVATION WELL K301
Date . _
(1984.) (EDT) (feet) Remarks
Hay 16
Depth to
Time
water
(EDT)
(feet)
0627
4.17
0656
4.16
0700
-
0709:45
4.16
0717:30
4.16
0723:48
4.16
0739
4.16
0749
4.16
0752
4.17
0802
4.16
0813
4.17
0836
4.16
0852
4.17
0901
4.17
0920
4.17
0935
4.18
0946
4.18
1001
4.18
1017
4.18
1031
4.17
1046
4.17
1101
4.17
1132
4.18
1201
4.18
1232
4.17
1301
4.18
1332
4.20
1400
4.18
1432
4.18
1501
4.18
1510
-
1514:34
4.18
1519:30
4.18
1528
4.18
1537
4.18
1547
4.18
1602
4.18
1611
4.18
1627
4.18
1704
4.18
1732
4.18
Pump on
Pump off
6-186
-------
TABLE A3
WATER LEVEL DATA FOR OBSERVATION WELL K303
Date
(198*0 (EDT) (feet) Remarks
May 16
Depth to
Time
water
(EDT)
(feet)
0629
6.07
0657
6.07
0700
-
0703:45
6.03
0710:45
6.04
0715:50
6.04
0725:40
6.07
0732
6.07
0741
6.08
0748
6.09
0753
6.09
0804
6.11
0812
6.11
0821
6.13
0835
6.14
0851
6.15
0902
6.15
0918
6.18
0932
6.20
0947
6.20
1001
6.22
1017
6.23
1032
6.22
1046
6.25
1102
6.25
1116
6.27
1131
6.25
1148
6.27
1201
6.29
1216
6.28
1234
6.29
1247
6.30
1302
6.30
1317
6.31
1333
6.32
1347
6.31
1401
6.32
1417
6.32
1433
6.32
1502
6.34
1510
-
1511:44
6.37
1513:10
6.36
1515:23
6.37
1518:36
6.36
1521
6.34
1525
6.35
1532
6.34
1535
6.33
1546
6.31
1601
6.30
1611
6.30
1627
6.28
1704
6.24
1733
6.23
Pump on
Pump off
6-187
-------
DRAWDOWN COMPUTATIONS FOR AQUIFER PUMPING TEST
Drawdowns in the pumped well and the observation wells during the
aquifer pumping test were computed based on the water level observations.
The drawdown computations for each well are tabulated in the tables which
follow. In these tables, the column headings have the following meaning:
Date:
Time:
At:
At':
Depth to water:
Date of reading.
Time of reading, Eastern Daylight
Time (EOT).
Time from start of pumping, in min-
utes.
Time since pumping stopped,
utes.
1n min-
Depth to water below the measuring
point, 1n feet.
Drawdown 1n water level, in feet.
Drawdown is computed by subtracting
the depth to water measured prior to
starting the test from the depth to
water. This drawdown is termed resi-
dual drawdown whenever At' is greater
than zero.
Remarks:
Any pertinent remarks.
6-188
-------
TABLE B1
DRAWDOWN COMPUTATIONS FOR WELL K3D2
Date
(1984)
Time
(EDT)
At
(mln)
At'
(mln)
At
St7"
Depth to
water
(feet)
s
(feet)
Remarks
May 16
0625
0658
0700
0700s10
0700: 30
0701
0702
0703
0704s15
0705
0706
0707
0708
0709
0710:05
0711:15
0712
0713
0714
0715
0716:38
0718:15
0719:38
0721
0723
0728
0730
0734
0736
0738
0740
0743
0747
0750
0755
0800
0811
0820
0830
0840
0850
0900
0915
0930
0945
1000
1016
1020
1030
1045
1052
1100
1115
1130
1146
1200
1215
1230
1245
1300
1315
0.0
0.17
0.50
1.0
2.0
3.0
4.25
5.0
6.0
7.0
8.0
9.0
10.08
11.25
12.0
13.0
14.0
15.0
16.6
18.25
19.6
21.0
23.0
28.0
30.0
34.0
36.0
38.0
40.0
43.0
47.0
50.0
55.0
60.0
71.0
80.0
90.0
100
110
120
135
150
165
180
196
200
210
225
232
240
255
270
286
300
315
330
345
360
375
5.85
5.85
12.00
14.10
14.59
15.00
15.53
15.65
15.79
15.79
15.97
15.91
15.96
16.02
15.94
15.89
15.91
16.18
16.10
16.06
15.93
16.04
16.30
16.29
16.31
16.35
16.38
16.39
16.40
16.43
16.43
16.37
16.34
16.39
16.39
16.38
16.47
16.45
16.52
16.58
16.60
16.83
16.79
16.88
16.87
17.14
17.17
17.10
17.23
17.17
16.93
16.87
17.11
17.01
17.01
17.00
17.03
17.04
17.01
17.04
0.00
0.00
6.15
8.25
8.74
9.15
9.68
9.80
9.94
9.94
10.12
10.06
10.11
10.17
10.09
10.04
10.06
10.33
10.25
10.21
10.08
10.19
10.45
10.44
10.46
10.50
10.53
10.54
10.55
10.58
10.58
10.52
10.49
10.54
10.54
10.53
10.62
10.60
10.67
10.73
10.75
10.98
10.94
11.03
11.02
11.29
11.32
11.25
11.38
11.32
11.08
11.02
11.26
11.16
11.16
11.15
11.18
11.19
11.16
11.19
Assume static water
level
Pump on
6-189
-------
TABLE B1
(continued)
DRAWDOWN COMPUTATIONS FOR WELL K3D2
Date
(1984)
Time
(EOT)
At
At1
At
(mln)
(mln)
SF"
390
405
4Z0
435
450
480
490
490.1
0.1
4901
490.6
0.6
818
491
1.0
491
492.5
2.5
197
493.7
3.7
133
494
4.0
123.5
495
5.0
99.0
496
6.0
82.7
497
7.0
71.0
498
8.0
62.2
499
9.0
55.4
500
10
50.0
502
12
41.8
504
14
36.0
507
17
29.8
510
20
25.5
514
24
21.4
517
27
19.1
520
30
17.3
525
35
15.0
532
42
12.7
536
46
11.7
540
50
10.8
550
60
9.2
566
76
7.4
603
113
5.3
630
140
4.5
Depth to
water
- s
(feet)
(feet)
17.02
11.17
17.02
11.17
17.02
11.17
17.05
11.20
17.08
11.23
17.00
11.15
13.00
7.15
8.00
2.15
7.68
1.83
7.31
1.46
7.18
1.33
7.13
1.28
7.07
1.22
7.02
1.17
6.95
1.10
6.91
1.06
6.87
1.02
6.83
0.98
6.79
0.94
6.73
0.88
6.69
0.84
6.63
0.78
6.57
0.72
6.55
0.70
6.51
0.66
6.47
0.62
6.42
0.57
6.40
0.55
6.36
0.51
6.32
0.47
6.25
0.40
6.15
0.30
6.12
0.27
Remarks
May 16 1330
(contInued)1345
1400
1415
1430
1500
1510
1510:06
1510:38
1511
1512:30
1513:40
1514
1515
1516
1517
1518
1519
1520
1522
1524
1527
1530
1534
1537
1540
1545
1552
1556
1600
1610
1626
1703
1730
Pump off
6-190
-------
TABLE B2
DRAWDOWN COMPUTATIONS FOR WELL K301
Date Time At
(1984) (EDT) (mln)
0700 0.0
0709:45 9.75
0717:30 17.5
0723:48 23.8
0739 39.0
0749 49.0
0752 52.0
0602 62.0
0613 73.0
0836 96.0
0852 112
0901 122
0920 140
0935 155
0946 166
1001 181
1017 197
1031 211
1046 226
1101 241
1132 272
1201 301
1232 332
1301 361
1332 392
1400 420
1432 452
1501 481
1510 490
Depth to
water s
(feet) (feet) Remarks
4.17
*•16 0 Assume static
water level
4.16
0
4.16
0
4.16
0
4.16
0
4.16
0
4.17
0.01
4.16
0
4.17
0.01
4.16
0
4.17
0.01
4.17
0.01
4.17
0.01
4.18
0.02
4.18
0.02
4.18
0.02
4.18
0.02
4.17
0.01
4.17
0.01
4.17
0.01
4.18
0.02
4.18
0.02
4.17
0.01
4.18
0.02
4.20
0.04
4.18
0.02
4.18
0.02
4.18
0.02
Pump off
6-191
-------
TABLE B3
DRAWDOWN COMPUTATIONS FOR WELL K303
Date
(1984)
Nay 16
Depth to
Time
At
water
s
(EDT)
(min)
(feet)
(feet)
0 629
6.07
0657
6.07
0
0700
0
07031»5
3.75
6.03
-0.04
0710:45
10.75
6.04
-0.03
0715:50
15.83
6.04
-0.03
0725:40
25.67
6.07
0
0732
32.0
6.07
0
0741
41.0
6.08
0.01
0748
48.0
6.09
0.02
0753
53.0
6.09
0.02
0804
64.0
6.11
0.04
0812
72.0
6.11
0.04
0821
81.0
6.13
0.06
0835
95.0
6.14
0.07
0851
111
6.15
0.08
0902
122
6.15
0.08
0918
138
6.18
0.11
0932
152
6.20
0.13
0947
167
6.20
0.13
1001
181
6.22
0.15
1017
197
6.23
0.16
1032
212
6.22
0.15
1046
226
6.25
0.18
1102
242
6.25
0.18
1116
256
6.27
0.20
1131
271
6.25
0.18
1148
288
6.27
0.20
1201
301
6.29
0.22
1216
316
6.28
0.21
1234
334
6.29
0.22
1247
347
6.30
0.23
1302
362
6.30
0.23
1317
377
6.31
0.24
1333
393
6.32
0.25
1347
407
6.31
0.24
1401
421
6.32
0.25
1417
437
6.32
0.25
1433
453
6.32
0.25
1502
482
6.34
0.27
1510
Remarks
Assume static
water level
Pump on
Pump off
6-192
-------
AQUIFER PUMPING TEST ANALYSIS
Water level data for the pumped well were used with the modified
Theis nonequilibrium analysis to compute the transmissivity for the
unconsolidated deposits. The form of the modified Theis nonequilibrium
analysis formula used for the computations is:
T = 2642
AS
The variables in the above equation have the following meaning:
T = transmissivity, in gallons per day per foot;
Q = average pumping rate, in gallons per minute; and
as = change in drawdown over one log-cycle for a semi-log plot of
time and drawdown.
The Theis recovery analysis, together with water level recovery
data for the pumped well, were also used to compute transmissivity. The
form of the Theis recovery analysis formula used for the computations is
the same as the modified Theis nonequilibrium analysis formula. However
for the Theis recovery analysis: '
as = change in residual drawdown over one log-cycle for a semi-log
plot of At/At' and residual drawdown. Time since pumping
began is defined as At and time since pumping stopped is
defined as At'.
The data plots and data analyses are presented in Figures CI and
C2.
6-19
-------
9.0
i i i i i » i i |
¦ i i i i i •
a*
i
M
VO
c
$
o
¦o
CO
S 10.5
T _ 264Q _ (264) (28.6)
&S 0.68
• 10.0
T = 11,100flpd/ft.
11.0-
11.5-
.« X •
12.0^
10 100
Time since pumping began (minutes)
1000
Figure C-l. Modified Theis nonequilibrium analysis using data from well K3D2.
-------
Figure C-2. Theis recovery analysis using data from well K3D2.
-------
SECTION 2
AQUIFER PUMPING TEST
AT
PINE KNOLL SHORES
6-197
-------
AQUIFER PUMPING TEST AT PINE KNOLL SHORES, NC
An 8-hour aquifer pumping test was performed on 4 August 1984 in
Pine Knoll Shores, NC. Pumping began at 0630 Eastern Daylight Time (EDT)
and lasted until 1430 EDT. Well P2C2 was the pumped well. The average
pumping rate from the well was 20.2 gallons per minute (gpm). The pumped
water was discharged to the yround surface approximately 300 feet north
of the well. Wells P2C1, P2C3 and P2C4 were used as observation wells.
Well construction details for the pumped well and the observation
wells varied between wells. Well P2C1 is completed in unconsolidated
sand deposits near the water-table surface. There is a two to three foot
thick layer of organic silt material that starts about one-half foot
below the base of this well. Well P2C3 is completed ii> unconsolidated
sand deposits about five feet above the top of a soft clay layer whose
thickness is approximately 13 feet. Well P2C2 is completed in uncon-
solidated sand deposits between the soft clay layer and the silt
material. Well P2C4 is completed below the base of the soft clay layer.
Construction details for the wells are summarized in Table 1. A cross-
section showing the lithology at the site and the spacial relationship
between wells is given in Figure 1.
Water levels were measured in the pumped well and each of the
observation wells. Water level declines were observed in the pumped well
and in observation wells P2C1 and P2C3. The water level in observation
well P2C4 rose slightly during the pumping period. The observed water
levels and computed water level changes during pumping are presented at
the end of this section.
The computed transmissivity and hydraulic conductivity for the
unconsolidated deposits are 15,800 gallons per day per foot (gpd/ft) and
445 gallons per day per foot squared (gpd/ft2). The aquifer thickness
used for the hydraulic conductivity computation was 35.5 feet. This
thickness represents that from the water table, approximately 5.5 feet
below land surface, to the top of the soft clay layer, approximately 41
feet below land surface.
The transmissivity of the unconsolidated deposits was computed
using data collected from the pumped well and from observation well P2C3.
The modified Theis nonequilibrium analysis (Ferris^t al., 1962) and the
Theis recovery analysis (Ferris et al., 1962), together with water level
data for the pumped well and from observation well P2C3, were used to
compute the transmissivity of the unconsolidated deposits*
The storage coefficient for the unconsolidated deposits was com-
puted to be 0.00045. This property of the unconsolidated deposits was
computed using the modified Theis nonequilibrium analysis and water level
data collected from observation well P2C3.
The aquifer pumping test analysis is presented at the end of this
section.
6-198
-------
TABLE 1
WELL CONSTRUCTION SUMMARY
Well
number
Well
depth
(feet)
Well
diameter
(inches)
Top of open
interval below
land surface
(feet)
Screen
length
(feet)
P2C1
10.6
6
5.6
5.0
P2C2
30.0
4
15.0
15.0
P2C3
37.0
2
32.0
5.0
P2C4
69.5
2
64.5
5.0
6-199
-------
20'-i
15.2'
SEA LEVEL—
-20'-
-40'-
-60'-
-80'—'
r-20'
10.6'
|<— 5.5' —
Land Surface
V
Sand
P2C1
*
P2C2
Sand
I
^
^Organic Silt
| P2C3
[
]P2C4
Sand
— SEA LEVEL
20'
--40'
60'
EXPLANATION
-80'
H
10 FEET
P2C3
Screen
V
A
Well ueed for aquifer pumping
teat and well number
Water Table
Figure 1. Geologic cross-section in vicinity of aquifer pump test
site at Pine Knoll Shores, N.C.
6-200
-------
The data collected at observation well P2C1 were not used for
determining the hydraulic properties of the unconsolidated deposits. A
preliminary analysis using the water level data from this observation
well indicated that drawdowns in the well were influenced by the presence
of the organic silt layer that lies between the open intervals for the
pumped well and the observation well.
The slight rise in water levels observed in observation well P2C4
during the aquifer pumping test suggests that the unconsolidated deposits
that lie below the soft clay layer are hydraulically separated from those
that lie above this layer. This well is completed in the unconsolidated
deposits below the soft clay layer. The data collected at well P2C4,
although qualitatively very informative, could not be used for any type
of quantitative analyses.
REFERENCES
Ferris, J.B. et al., 1962. Theory of aquifer tests: United States
Geological Survey Water-Supply Paper 1536-E.
6-201
-------
WATER LEVELS FOR AQUIFER PUMPING TEST
Water levels were recorded for the pumped well (Well P2C2) and for
wells P2C1, P2C3 and P2C4 during the aquifer pumping test. These data
are tabulated by well number in the tables which follow. In these
tables, the column headings have the following meaning:
Date: Date of reading.
Time: Time of reading, Eastern Daylight
Time (EDT).
Depth to water: The depth to water below the
measuring point, in feet.
Flow meter reading: The total gallons of flow recorded by
(pimped well only) the flow meter. The meter reading
was 184.1 gallons prior to beginning
the test.
Remarks: Any pertinent remarks.
6-202
-------
TABLE A1
WATER LEVEL AND PUMPING DATA FOR WELL P2C2
Date
(1984)
Time
(EDT)
Depth to
water
(feet)
Flow meter
reading
(gallons)
Remarks
August 4
0607
0615
0620
0629:30
0630
0630:14
0630:24
0630:30
0630:45
0631
0631:15
0631:30
0631:45
0632
0633
0634
0635
0636
0638
0640
0643
0645
0650
0655
0656
0657
0700
0707
0710
0715
0720
0730
0746
0749
0750
0800
0813
0815
0819
0830
0845
0848
0850
0900
0915
0918
0920
0930
0933
0934
0945
1000
1003
1015
1017
1030
1032
1033
1100
1102
1103
1131
1137
1200
5.13
5.13
5.12
5.12
8.00
10.00
10.61
11.23
11.45
11.57
11.61
11.68
11.71
11.78
11.81
11.84
11.84
11.86
11.89
11.92
11.95
11.97
11.99
12.02
12.05
12.07
12.10
12.13
12.15
12.18
12.18
12.21
12.24
12.24
12.26
12.27
12.28
12.31
12.33
12.31
12.37
184.1
450
740
1100
1830
2400
3000
3610
3930
4520
4800
5100
5710
6410
Pump on
Measure 20.7 gpm using flow meter
Measure 20.6 gpm using flow meter
Measure 20.7 gpm using flow meter
Measure 20.4 gpm using flow meter
Measure 20.5 gpm using flow meter
Measure 20.5 gpm using flow meter
Measure 20.4 gpm using flow meter
Measure 20.3 gpm using flow meter
Measure 20.3 gpm using flow meter
Measure 20.3 gpm using flow meter
Measure 20.3 gpm using flow meter
Measure 20.3 gpm using flow meter
Measure 20.2 gpm using flow meter
Measure 20.3 gpm using flow meter
Measure 20.2 gpm using flow meter
Measure 20.2 gpm using flow meter
6-203
-------
TABLE A1
(continued)
WATER LEVEL AND PUMPING DATA FOR WELL P2C2
Depth to
Date
(1984)
Time
water
(EDT)
(feet)
1203
1205
1234
12.40
1237
1238
12.40
1300
1303
1305
12.44
1330
1333
1334
1400
12.45
1403
1404
1429
12.48
1430
10.00
1430s07
1430:15
8.00
1430:30
6.62
1431
6.00
1431:30
5.85
1432
5.80
1433
5.75
1434
5.72
1435
5.71
1436
5.69
1437
5.69
1438:30
5.68
1441
5.70
1443
5.69
1445
5.64
1448
5.64
1450
5.64
1453
5.63
1455
5.62
1458
5.61
1500
5.61
1504
5.60
1508
5.59
1515
5.58
1520
5.55
1530
5.55
1540
5.54
1550
5.54
1600
5.51
1615
5.51
1630
5.49
1707
5.47
1732
5.45
1801
5.54
1827
5.45
1909
5.41
1941
5.41
1025
5.30
Flow meter
reading
(gallons)
Remarks
August 4
(continued)
6930
7630
8140
8750
9350
9896.6
Measure 20.2 gpm using flow meter
Measure 20.1 gpm using flow meter
Measure 20.1 gpm using flow meter
Measure 20.2 gpm using flow meter
Measure 20.1 gpm using flow meter
Pump off
August 5
Total gallons pumped Is 9,712.5 gallons
Average pumping rate Is 20.2 gpm
6-204
-------
TABLE A2
WATER LEVa DATA FOR OBSERVATION WELL P2C1
Date
(1984)
Time
(EDT)
August 4
0605
0619
0630
0632:30
0634s 30
0637.
0642
0646
0653
0658
0708
0718
0731
0744
0801
0814
0829
0844
0859
0914
0929
0959
1014
1029
1058
1132
1159
1233
1259
1329
1359
1426
1430
1433»30
1435s30
1437 s 30
143?
1442
1446
1451
1456
1501
1508
1514
1519
1529
1539
1549
1559
1614
1632
1706
1736
1805
1910
1934
Depth to
water
(feet)
Remarks
6.31
6.32
6.56
6.6 3
6.68
6.70
6.76
6.80
6.83
6.89
6.94
6.99
7.02
7.07
7.10
7.12
7.14
7.17
7.18
7.21
7.23
7.25
7.28
7.31
7.35
7.38
7.43
7.43
7.45
7.47
7.49
7.23
7.20
7.18
7.15
7.15
7.09
7.06
7.04
7.03
7.00
6.98
6.96
6.92
6.91
6.87
6.87
6.83
6.82
6.79
6.75
6.74
6.69
6.68
Pump on
Pump off
August 5
1023
6.55
6-205
-------
TABLE A3
WATER LEVEL DATA FOR OBSERVATION WELL P2C3
Date
(198fr) (EDT) (feet) Remarks
August 4
August 5
Depth to
Time
water
(EDT)
(feet)
0608
4.87
0621
4.86
0630
0633:30
5.98
0635:30
6.04
0639
6.09
0644
6.12
0649
6.14
0654
6.14
0659
6.18
0709
6.19
0721
6.23
0732
6.24
0745
6.24
0802
6.30
0816
6.32
0831
6.32
0846
6.35
0901
6.37
0916
6.38
0931
6.40
0946
6.42
1001
6.43
1016
6.44
1031
6.47
1059
6.48
1133
6.49
1202
6.50
1235
6.53
1301
6.56
1331
6.57
1401
6.53
1427
6.60
1430
1432:30
5.61
1434:30
5.46
1436:30
5.42
1438
5.41
1444
5.38
1447
5.36
1452
5.35
1457
5.33
1459
5.34
1502
5.32
1511
5.31
1516
5.30
1521
5.25
1531
5.28
1533
5.28
1541
5.27
1551
5.26
1601
5.24
1616
5.23
1631
5.22
1708
5.20
1733
5.19
1802
5.17
1828
5.17
1908
5.15
1932
5.14
1026
5.04
Pump on
Pump off
6-206
-------
TABLE A4
WATER LEVEL DATA FOR OBSERVATION WELL P2C4
Date
(1984) (EDT) (feet) Remarks
August 4
August 5
Depth to
Time
water
(EDT)
(feet)
0610
5.59
0622
5.59
0630
0641
5.58
0651
5.56
0711
5.53
0722
5.52
0733
5.52
0747
5.52
0803
5.52
0817
5.53
0847
5.52
0917
5.52
0932
5.52
0947
5.52
1002
5.52
1032
5.52
1101
5.52
1134
5.51
1202
5.52
1236
5.52
1332
5.51
1428
5.51
1430
1440
5.51
1449
5.51
1454
5.52
1503
5.52
1517
5.52
1532
5.52
1602
5.52
1633
5.53
1709
5.52
1734
5.53
1803
5.53
1907
5.54
1027
5.56
Pump on
Pump off
6-207
-------
DRAWDOWN COMPUTATIONS FOR AQUIFER PUMPING TEST
Drawdowns in the pumped well and in the observation wells during
the aquifer pumping test were computed based on the water-level obser-
vations. The drawdown computations for these wells are tabulated in the
tables which follow. In these tables, the column headings have the
following meaning:
Date: Date of reading.
Time: Time of reading, Eastern Daylight
Time (EDT).
At: Time from start of pumping, in
mi nutes.
At': Time since pumping stopped, in min-
utes.
Depth to water: Depth to water below the measuring
point, in feet.
Trend Corr.: A correction to account for the
natural trend in water levels. The
correction is based on the observed
water level trend in well P2C1 during
the period August 6-20, 1984.
Drawdown in the well, in feet.
Drawdown is computed by adding the
trend correction to the depth to
water measurement and substracting
from this total the depth to water
measured at approximately 0620 EDT on
August 4, 1984.
A correction to account for dewater-
ing of the aquifer system, in
feet. The saturated thickness of
the aquifer system in the vicinity of
the well prior to pumping is repre-
sented by M. For these computations
the value for M is 35.i feet.
The drawdown in the well corrected
for the effects of dewatering, in
feet. This drawdown is termed resi-
dual drawdown whenever At' is greater
than zero.
Any pertinent remarks.
s2/2M:
s':
Remarks:
6-208
-------
TABLE 81
DRAWDOWN COMPUTATIONS FOR
Depth to Trend
Date Time At At' At water corr.
(1984) (EOT) (win) (win) 5F (feet) (feet)
0629:30
5.12
0630
0630:14
0.23
8.00
0
0630:24
0.40
10.00
0
0630:30
0.50
10.61
0
0630:45
0.75
11.23
0
0631
1.0
11.45
0
0631:15
1.25
11.57
0
0631:30
1.50
11.61
0
0631:45
1.75
11.68
0
0632
2.0
11.71
0
0633
3.0
11.78
0
0634
4.0
11.81
0
0635
5.0
11.84
0
0636
6.0
11.84
0
0638
8.0
11.86
0
0640
10
11.89
0
0645
15
11.92
0
0650
20
11.95
0
0655
25
11.97
0
0700
30
11.99
0
0710
40
12.02
0
0720
50
12.05
0
0730
60
12.07
0
0746
76
12.10
0
0800
90
12.13
-0.01
0815
105
12.15
-0.01
0830
120
12.18
-0.01
0845
135
12.18
-0.01
0900
150
12.21
-0.01
0915
165
12.24
-0.01
0930
180
12.24
-0.01
0945
195
12.26
-0.01
1000
210
12.27
-0.01
1015
225
12.28
-0.01
1030
240
12.31
-0.01
1100
270
12.33
-0.01
1131
301
12.31
-0.01
1200
330
12.37
-0.01
1234
364
12.40
-0.02
1300
390
12.40
-0.02
1330
420
12.44
-0.02
1400
450
12.45
-0.02
1429
479
12.48
-0.02
1430
480
WELL P2C2
2
s
s "2R s1
(feet) (feet) (feet) Remarks
Assume static water level
Pump on
2.88
0.12
2.76
4.88
0.34
4.54
5.49
0.42
5.07
6.11
0.53
5.58
6.33
0.56
5.77
6.45
0.59
5.86
6.49
0.59
5.90
6.56
0.61
5.95
6.59
0.61
5.98
6.66
0.62
6.04
6.69
0.63
6.06
6.72
0.64
6.08
6.72
0.64
6.08
6.74
0.64
6.10
6.77
0.65
6.12
6.80
0.65
6.15
6.83
0.66
6.17
6.85
0.66
6.19
6.87
0.66
6.21
6.90
0.67
6.23
6.93
0.68
6.25
6.95
0.68
6.27
6.98
0.69
6.29
7.00
0.69
6.31
7.02
0.69
6.33
7.05
0.70
6.35
7.05
0.70
6.35
7.08
0.71
6.37
7.11
0.71
6.40
7.11
0.71
6.40
7.13
0.72
6.41
7.14
0.72
6.42
7.15
0.72
6.43
7.18
0.73
6.45
7.20
0.73
6.47
7.18
0.73
6.45
7.24
0.74
6.50
7.26
0.74
6.52
7.26
0.74
6.52
7.30
0.75
6.55
7.31
0.75
6.56
7.34
0.76
6.58
Pump off
-------
TABLE B1
(continued)
DRAWDOWN COMPUTATIONS FOR WELL P2C2
Date
(198*0
August 4
(continued)
August 5 1025
Time
(EOT)
At
(win)
At'
(win)
At
St
Depth to
water
(feet)
Trend
corr.
(feet)
s
(feet)
2
s
7R
(feet)
s'
(feet)
1*30:07
480.1
0.12
4001
10.00
-0.02
4.86
0.33
4.53
1430:15
480.2
0.25
1921
8.00
-0.02
2.86
0.12
2.74
1430:30
480.5
0.50
961
6.62
-0.02
1.48
0.03
1.45
1431
481
1.0
481
6.00
-0.02
0.86
0.01
0.85
1431:30
481.5
1.5
321
5.85
-0.02
0.71
0.01
0.70
1432
482
2.0
241
5.80
-0.02
0.66
0.01
0.65
1433
483
3.0
161
5.75
-0.02
0.61
0
0.61
1434
484
4.0
121
5.72
-0.02
0.58
0
0.58
1435
485
5.0
97.0
5.71
-0.02
0.57
0
0.57
1436
486
6.0
81.0
5.69
-0.02
0.55
0
0.55
1437
487
7.0
69.6
5.69
-0.02
0.55
0
0.55
1436:30
488.5
8.5
57.5
5.68
-0.02
0.54
0
0.54
1441
491
11
44.6
5.70
-0.02
0.56
0
0.56
1443
493
13
37.9
5.69
-0.02
0.55
0
0.55
1445
495
15
33.0
5.64
-0.02
0.50
0
0.50
1448
498
18
27.7
5.64
-0.02
0.50
0
0.50
1450
500
20
25.0
5.64
-0.02
0.50
0
0.50
1453
503
23
21.9
5.63
-0.02
0.49
0
0.49
1455
505
25
20.2
5.62
-0.02
0.48
0
0.48
1458
508
28
18.1
5.61
-0.02
0.47
0
0.47
1500
510
30
17.0
5.61
-0.02
0.47
0
0.47
1504
514
34
15.1
5.60
-0.02
0.46
0
0.46
1508
518
38
13.6
5.59
-0.02
0.45
0
0.45
1515
525
45
11.7
5.58
-0.02
0.44
0
0.44
1520
530
50
10.6
5.55
-0.02
0.41
0
0.41
1530
540
60
9.00
5.55
-0.02
0.41
0
0.41
1540
550
70
7.86
5.54
-0.02
0.40
0
0.40
1550
560
80
7.00
5.54
-0.02
0.40
0
0.40
1600
570
90
6.33
5.51
-0.03
0.36
0
0.36
1615
585
105
5.57
5.51
-0.03
0.36
0
0.36
1630
600
120
5.00
5.49
-0.03
0.34
0
0.34
1707
637
157
4.06
5.47
-0.03
0.32
0
0.32
1732
662
182
3.64
5.45
-0.03
0.30
0
0.30
1601
691
211
3.27
5.54
-0.03
0.39
0
0.39
1827
717
237
3.03
5.45
-0.03
0.30
0
0.30
1909
759
279
2.72
5.41
-0.03
0.26
0
0.26
1941
791
311
2.54
5.41
-0.03
0.26
0
0.26
1025
1675
1195
1.40
5.30
-0.07
0.11
0
0.11
Remarks
-------
TABLE B2
DRAWDOWN COMPUTATIONS FOR WELL P2C1
Depth to Trend s
Date Time At At' At water corr. s 2R s'
(1984) (EDT) (wiln) (mln) ST (feet) (feet) (feet) (feet) (feet) Remarks
August 4
0619
6.32
0630
0632:30
2.5
6.56
0
0.24
0
0.24
0634:30
4.5
6.63
0
0.31
0
0.31
0637
7.0
6.68
0
0.36
0
0.36
0642
12
6.70
0
0.38
0
0.38
0648
18
6.76
0
0.44
0
0.44
0653
23
6.80
0
0.48
0
0.48
0658
28
6.83
0
0.51
0
0.51
0708
38
6.89
0
0.57
0
0.57
0718
48
6.94
0
0.62
0.01
0.61
0731
61
6.99
0
0.67
0.01
0.66
0744
74
7.02
0
0.70
0.01
0.69
0801
91
7.07
-0.01
0.74
0.01
0.73
0814
104
7.10
-0.01
0.77
0.01
0.76
0829
119
7.12
-0.01
0.79
0.01
0.78
0844
134
7.14
-0.01
0.81
0.01
0.80
0859
149
7.17
-0.01
0.84
0.01
0.83
0914
164
7.18
-0.01
0.85
0.01
0.84
0929
179
7.21
-0.01
0.88
0.01
0.87
0959
209
7.23
-0.01
0.90
0.01
0.89
1014
224
7.25
-0.01
0.92
0.01
0.91
1029
239
7.28
-0.01
0.95
0.01
0.94
1058
268
7.31
-0.01
0.98
0.01
0.97
1132
302
7.35
-0.01
1.02
0.01
1.01
1159
329
7.38
-0.01
1.05
0.02
1.03
1233
363
7.43
-0.02
1.09
0.02
1.07
1259
389
7.43
-0.02
1.09
0.02
1.07
1329
419
7.45
-0.02
1.11
0.02
1.09
1359
449
7.47
-0.02
1.13
0.02
1.11
1426
476
7.49
-0.02
1.15
0.02
1.13
1430
480
1433:30
483.5
3.5
138
7.23
-0.02
0.89
0.01
0.88
1435:30
485.5
5.5
88.3
7.20
-0.02
0.86
0.01
0.85
1437:30
487.5
7.5
65.0
7.18
-0.02
0.84
0.01
0.83
1439
489
9.5
51.5
7.15
-0.02
0.81
0.01
0.80
1442
492
12
41.0
7.15
-0.02
0.81
0.01
0.80
1446
496
16
31.0
7.09
-0.02
0.75
0.01
0.74
1451
501
21
23.9
7.06
-0.02
0.72
0.01
0.71
1456
506
26
19.5
7.04
-0.02
0.70
0.01
0.69
1501
511
31
16.5
7.03
-0.02
0.69
0.01
0.68
1508
518
38
13.6
7.00
-0.02
0.66
0.01
0.65
1514
524
44
11.9
6.98
-0.02
0.64
0.01
0.63
1519
529
49
10.8
6.96
-0.02
0.62
0.01
0.61
Assune static water level
Pump on
Pump off
-------
Tiae
(EOT)
1529
1539
15*9
1559
1614
1632
1706
1736
1805
1910
1934
1023
TABLE B2
(continued)
DRAWDOWN COMPUTATIONS FOR WELL P2C1
2
At
(¦In)
Af
(¦in)
At
Kt
Depth to
.water
(feet)
Trend
corr.
(feet)
s
(feet)
s
"2R
(feet)
s'
(feet)
539
59
9.14
6.92
-0.02
0.58
0
0.58
549
69
7.96
6.91
-0.02
0.57
0
0.57
559
79
7.08
6.87
-0.02
0.53
0
0.53
569
89
6.39
6.87
-0.02
0.53
0
0.53
584
104
5.62
6.83
-0.03
0.48
0
0.48
602
122
4.93
6.82
-0.03
0.47
0
0.47
636
156
4.08
6.79
-0.03
0.44
0
0.44
666
186
3.58
6.75
-0.03
0.40
0
0.40
695
215
3.23
6.74
-0.03
0.39
0
0.39
760
280
2.71
6.69
-0.03
0.34
0
0.34
794
304
2.58
6.68
-0.03
0.33
0
0.33
1673
1193
1.40
6.55
-0.07
0.16
0
0.16
-------
TABLE B3
DRAWDOWN COMPUTATIONS FOR WELL P2C3
Date
(1984)
Depth to
Trend
Ti«e
At
At'
At
water
corr.
s
(EDT)
(win)
(¦In)
St
(feet)
(feet)
(feet)
0621
4.86
0630
1.12
0633:30
3.5
5.98
0
0635:30
5.5
6.04
0
1.18
0639
9.0
6.09
0
1.23
0644
14
6.12
0
1.26
0649
19
6.14
0
1.28
0654
24
6.14
0
1.28
0659
29
6.18
0
1.32
0709
39
6.19
0
1.33
0721
51
6.23
0
1.37
0732
62
6.24
0
1.38
0745
75
6.24
0
1.38
0802
92
6.30
-0.01
1.43
0616
106
6.32
-0.01
1.45
0831
121
6.32
-0.01
1.45
0846
136
6.35
-0.01
1.48
0901
151
6.37
-0.01
1.50
0916
166
6.38
-0.01
1.51
0931
181
6.40
-0.01
1.53
0946
196
6.42
-0.01
1.55
1001
211
6.43
-0.01
1.56
1016
226
6.44
-0.01
1.57
1031
241
6.47
-0.01
1.60
1059
269
6.48
-0.01
1.61
1133
303
6.49
-0.01
1.62
1202
332
6.50
-0.02
1.62
1235
365
6.53
-0.02
1.65
1301
391
6.56
-0.02
1.68
1331
421
6.57
-0.02
1.69
1401
451
6.53
-0.02
1.65
1427
477
6.60
-0.02
1.72
1430
480
0.73
1432:30
482.5
2.5
193
5.61
-0.02
1434:30
484.5
4.5
108
5.4 6
-0.02
0.58
1436:30
486.5
6.5
74.8
5.42
-0.02
0.54
1438
488
8.0
61.0
5.41
-0.02
0.53
1444
494
14
35.3
5.38
-0.02
0.50
1447
497
17
29.2
5.36
-0.02
0.48
1452
502
22
22.8
5.35
-0.02
0.47
1457
507
27
18.8
5.33
-0.02
0.45
1459
509
29
17.6
5.34
-0.02
0.46
1502
512
32
16.0
5.32
-0.02
0.44
1511
521
41
12.7
5.31
-0.02
0.43
1516
526
46
11.4
5.30
-0.02
0.42
August 4
ST>
L
U)
"ZH s'
(feet) (feet)
Remarks
As suae static water level
Pi«p on
0.02
1.10
0.02
1.16
0.02
1.21
0.02
1.24
0.02
1.26
0.02
1.26
0.02
1.30
0.02
1.31
0.03
1.34
0.03
1.35
0.03
1.35
0.03
1.40
0.03
1.42
0.03
1.42
0.03
1.45
0.03
1.47
0.03
1.48
0.03
1.50
0.03
1.52
0.03
1.53
0.03
1.54
0.04
1.56
0.04
1.57
0.04
1.58
0.04
1.58
0.04
1.61
0.04
1.64
0.04
1.65
0.04
1.61
0.04
1.68
0.01
0.72
0
0.58
0
0.54
0
0.53
0
0.50
0
0.48
0
0.47
0
0.45
0
0.46
0
0.44
0
0.43
0
0.42
-------
Time
(EDT)
1521
1531
1533
1541
1551
1601
1616
1631
1708
1733
1802
1828
1908
1932
1026
TABLE B3
(continued)
DRAWDOWN COMMUTATIONS FOR WELL P2C3
Depth to
Trend
At
At'
At
water
corr.
(mln)
(mln)
It'
(feet)
(feet)
531
51
10.4
5.25
-0.02
541
61
8.87
5.28
-0.02
543
63
8.62
5.28
-0.02
551
71
7.76
5.27
-0.02
561
81
6.93
5.26
-0.02
571
91
6.27
5.24
-0.03
586
106
5.53
5.23
-0.03
601
121
4.97
5.22
-0.03
638
158
4.04
5.20
-0.03
663
183
3.62
5.19
-0.03
692
212
3.26
5.17
-0.03
718
238
3.02
5.17
-0.03
758
278
2.73
5.15
-0.03
782
302
2.59
5.14
-0.03
1676
1196
1.40
5.04
-0.07
2
s
s "2R s'
(feet) (feet) (feet) Remarks
0.37 0 0.37
0.40 0 0.40
0.40 0 0.40
0.39 0 0.39
0.38 0 0.38
0.35 0 0.35
0.34 0 0.34
0.33 0 0.33
0.31 0 0.31
0.30 0 0.30
0.28 0 0.28
0.28 0 0.28
0.26 0 0.26
0.25 0 0.25
0.11 0 0.11
-------
TABLE B4
DRAWDOWN COMPUTATIONS FOR WELL P2C4
Date
(1984)
August 4
August 5
Depth to
Trend
Time
At
At'
At
water
corr.
s
(EDT)
(min)
(min)
At
(feet)
(feet)
(feet)
0610
5.59
0
0622
5.59
0
0630
0
06*1-1
11
5.58
0
-0.01
0651
21
5.56
0
-0.03
0711
41
5.53
0
-0.06
0722
52
5.52
0
-0.07
0733
63
5.52
0
-0.07
0747
77
5.52
- 0
-0.07
0803
93
5.52
-0.01
-0.08
0817
107
5.53
-0.01
-0.09
0847
137
5.52
-0.01
-0.08
0917
167
5.52
-0.01
-0.08
0932
182
5.52
-0.01
-0.08
0947
197
5.52
-0.01
-0.08
1002
212
5.52
-0.01
-0.08
1032
242
5.52
-0.01
-0.08
1101
271
5.52
-0.01
-0.08
1134
304
5.51
-0.01
-0.09
1202
332
5.52
-0.01
-0.08
1236
366
5.52
-0.02
-0.09
1332
422
5.51
-0.02
-0.10
1428
478
5.51
-0.02
-0.10
1430
480
1440
490
10
49.0
5.51
-0.02
-0.10
1449
499
19
26.3
5.51
-0.02
-0.10
1454
504
24
21.0
5.52
-0.02
-0.09
1503
513
33
15.5
5.52
-0.02
-0.09
1517
527
47
11.2
5.52
-0.02
-0.09
1532
542
62
8.74
5.52
-0.02
-0.09
1602
572
92
6.22
5.52
-0.03
-0.10
1633
603
123
4.90
5.53
-0.03
-0.09
1709
639
159
4.02
5.52
-0.03
-0.10
1734
664
184
3.61
5.53
-0.03
-0.09
1803
693
213
3.25
5.53
-0.03
-0.09
1907
757
277
2.73
5.54
-0.03
-0.08
1027
1677
1197
1.40
5.56
-0.07
-0.10
Remarks
Assume static water level
Pump on
Pump off
-------
AQUIFER PUMPING TEST ANALYSIS
Water level data for the pumped well and for observation well P2C3
were used to compute the hydraulic properties of the unconsolidated depo-
sits. The modified Theis nonequilibrium analysis using water level data
for the pumped well and observation well P2C3 were used to compute
transmissivity. The Theis recovery analysis, together with water level
recovery data for the pumped well and observation well P2C3, were also
used to compute transmissivity. The storage coefficient was computed
using the modified Theis nonequilibrium analysis and water level data for
observation well P2C3.
Water level data collected during the latter part of testing were
used to compute the hydraulic properties of the aquifer. The later data
represent a sampling of the hydraulic properties of the shallow aquifer
system over a larger area and are more representative of average con-
ditions in the aquifer.
The behavior of the early drawdown and recovery data indicated that
a barrier boundary was present in the vicinity of the pumped well.
However, the lithologic data available from other boreholes in the vici-
nity of the test well strongly precluded the existence of any such bound-
ary. The behavior of the observed data probably reflects the integrated
effects of nonhomogeneity and anisotropy in the shallow aquifer over the
area tested. A nonhomogeneous aquifer is one in which the hydraulic pro-
perties change spatially. A anisotropic aquifer is one whose horizontal
hydraulic conductivity is different from its vertical hydraulic conduc-
tivity.
The modified Theis nonequilibrium analysis formula used for com-
puting transmissivity is:
T = 264Q
AS
The variables in the above equation have the following meaning:
T = transmissivity, in gallons per day per foot;
Q = average pumping rate, in gallons per minute; and
as ¦ change in drawdown over one log-cycle for a semi-log plot of
time and drawdown.
The form of the Theis recovery analysis fomhila used for the
transmissivity computation is the same as the form of the modified Theis
nonequilibrium analysis formula used for this computation. However, for
the Theis recovery analysis:
as = change in residual drawdown over one log-cycle for a semi-log
plot of At/At' and residual drawdown. Time since pumping began
is defined by At and time since pumping stopped is defined by
At'.
6-216
-------
The modified Theis nonequilibrium analysis formula used for com-
puting the storage coefficient is:
2.09 x 10"4Ttn
S = 2
rc
The variables in this equation that have not previously been defined
have the following meanings:
S = storage coefficient, no dimensions;
tQ = the time at which a straight line drawn through the data
intercepts the zero drawdown line for a semi-loy plot of time
and drawdown, in minutes; and
r = distance from pumping well to observation well, in feet.
The data plots and data analyses are presented in Figures CI, C2,
C3 and C4.
6-217
-------
6.1-
6.2 -
«T>
t
to
H
CD
© 6.3 -
e
*o
J 6.4
k-
o
6.5-
T =
264Q _ (264) (20.2)
A 8 (0.40)
T = 13,300gpd/ft,
6.6-
10 100
Time since pumping began (minutes)
Figure C-l. Modified Theis nonequilibrium analysis using data from well P2C2.
iS i I I
1000
-------
OJr
i i i i t i |
I V • V V I V I |
I I' I I I I I I
o.e-
0.5 —
*
*
o
"O
*
<9
I
to
vO
3 0.3-
2
m
©
oc
T = 2640 = t264><202)
A s (0.30)
0.2-
T = 17,800gpd/ft.
i i
¦ ..... i
10
At/At'
-i i i i i—t-
100
¦ ' -
1000
Figure C-2. Theis recovery analysis using data from well P2C2.
-------
1.2 -
V
to - 0.038min.
*
2 1.5h
Q
1.6
T =
T =
S =
S =
264Q _ (264K20.2)
AS 0.41
13.000 gpd/ft.
2.09 X10"4 T to
(2.09 X10^X13,000X0.038)
(15.22)
S = 4.5X10
-4
10 100
Time since pumping begsn (minutes)
1000
Figure C-3. Modified Theis nonequilibrium analysis using data from well P2C3.
-------
i ~ r
i i i i I
t i i
0.3-
T - 264Q - (264X20.2)
as (0.28)
T = 19,000gpd/ft.
¦ ' i>i
1 * *
' ' ' >¦.«.«
' ' « ¦ ¦ ' '
10
At/At'
100
Figure C-4. Theis recovery analysis using data from well P2C3.
-------
SECTION 3
AQUIFER PUMPING TEST
AT
SURF CITY
6-223
-------
AQUIFER PUMPING TEST AT SURF CITY, NC
A 4-hour aquifer pumping test was performed on August 2, 1984 in
Surf City, NC. Pumping began at 0931 Eastern Daylight Time (EDT) and
lasted until 1331 EDT. Well S3B2 was the pumped well. The average
pumping rate from the well was 9.5 gallons per minute (gpm). The pumped
water from the well was dischaged to a holding tank until about 1130 EDT
by which time the tank was full. The pumped water was then discharged
into a slight depression located about 100 feet north of the test site.
Wells S3B1, S3B3, S3B4 and S3B5 were used as observation wells.
Well construction details for the pumped well and the observation
wells varied between wells. Well S3B1 is completed in unconsolidated
sand deposits near the water-table surface. Wells S3B2 and S3B5 are
completed in unconsolidated sand deposits about five feet above the top
of limestone bedrock and about one foot above a two foot thick sandy to
silty clay layer that occurs at the interface between the limestone and
unconsolidated sand. Well S3B3 is completed in the limestone about 10
feet below the limestone surface. Well S3B4 is completed in the
limestone about 60 feet below this surface. Construction details for the
wells are summarized in Table 1. A cross-section showing the lithology
at the site and the spacial relationship between wells is given in Figure
1.
Water levels were measured in the pumped well and each of the obser-
vation wells. Water-level declines were observed in the pumped well and
in wells S3B1 and S3B5. The water level in wells S3B3 and S3B4 rose
during the pumping period. The observed water levels and computed water
level changes during pumping are presented at the end of this section.
The computed transmissivity and hydraulic conductivity for the
unconsolidated deposits are 16,900 gallons per day per foot (gpd/ft) and
650 gallons per day per foot squared (gpd/ft2). The aquifer thickness
used for the hydraulic conductivity computation was 27 feet. This
thickness represents that from the water table approximately 6 feet below
land surface to the top of the sandy to silty clay layer approximately 33
feet below land surface.
The transmissivity of the unconsolidated deposits was computed using
data collected from the pumped well and from observation wells S3B1 and
S3B5. The modified Theis nonequilibrium analysis (Ferris et al., 1962),
together with water-level data for the pumped well, were used to compute
the transmissivity of the unconsolidated deposits. Type curves developed
by Stallman (Lohman, 1972) for a pumping well penetrating the bottom
three-tenths of a water-table aquifer, together with water-level data
collected from observation wells S3B1 and S3B5, wire also used to compute
transmissivity.
The storage coefficient for the unconsolidated deposits was found to
be 0.04 and the vertical hydraulic conductivity for these deposits was
computed to be 497 gpd/ft2. The storage coefficient was computed using
the type curves described above and water-level data collected from
observation wells S3B1 and S3B5. The vertical hydraulic conductivity was
computed using these type curves and water-level data collected from
observation well S3B1.
6-224
-------
TABLE 1
WELL CONSTRUCTION SUMMARY
Well
number
Well
depth
(feet)
Well
diameter
(inches)
Top of open
interval below
land surface
(feet)
Screen
length
(feet)
S3B1
14.2
6
8.6
5.6
S3B2
29.8
2
24.8
5.0
S3B3
48.6
2
43.6
5.0
S3B4
124
2
119
5.0
S3B5
28.4
4
24.2
4.2
6-225
-------
20'-
SEA LEVELH
-20'-\
-40 H
-60H
-80M
-100H
-120'
9.0'-
Land Surface
— 6.0'—
Sand
S3B2|
Sandy to silty clay
I
S3B1 Q
S3B5 |
S3B3
Limestone
[[] S3B4
EXPLANATION _
r*20'
Hsea level
r~ -20'
40'
—60'
80'
—100'
I—120'
H
10 feet
S3B1
Screen |j
V
Well used for aquifer pumping
test and well number
Water Table
Figure 1. Geologic cross-section in vicinity of aquifer pump test
site at Surf City, N.C.
6-226
-------
The aquifer pumping test analysis is presented at the end of this
section.
The rise in water levels observed in wells S3B3 and S3B4 during the
aquifer pumping test suggests that the unconsolidated sand and limestone
bedrock are hydraulically separated. These wells are completed in the
limestone bedrock. The data collected at wells S3B3 and S3B4, although
qualitatively informative, could not be used for any type of quantitative
analyses.
REFERENCES
Ferris, J.B. et al., 1962. Theory of aquifer tests: United States
Geological Survey Water-Supply Paper 1536-E.
Lohman, S.W. 1972. Ground-water hydraulics: United States Geological
Survey Professional Paper 708.
6-227
-------
WATER LEVELS FOR AQUIFER PUMPING TEST
Water levels were recorded for the pumped well (Well S3B2) and for
wells S3B1, S3B3, S3B4 and S3B5. These data are tabulated for each well
in the tables which follow. In these tables, the column headings have
the following meanings:
Date:
Time:
Depth to water:
Flow meter reading:
(Pumped well only)
Date of reading.
Time of reading, Eastern Daylight Time
(EOT).
The depth to water below the measuring
point, 1n feet.
The total gallons of water recorded by
the flow meter. The meter reading was
994424.7 gallons prior to beginning the
test.
Remarks:
Any pertinent remarks.
6-228
-------
TABLE A1
WATER LEVEL AND PUMPING DATA FOR WELL S3B2
Date
(1984)
Depth to
Time
water
(EOT)
(feet)
0847
6.03
0930
6.03
0931
-
0931:28
15.77
0931:45
15.96
0932
15.98
0932:20
15.98
0932:40
15.98
0933
16.04
0933:20
16.03
0933:40
16.04
0934
16.04
0936
16.08
0937:30
16.05
0938
0940
16.07
0943
16.09
0944
-
0946:30
16.08
0950
16.09
0955
16.05
0957
-
0958
-
1000
16.07
1012
16.09
1021
16.09
1031
16.08
1033
-
1045
16.07
1101
16.08
1102
-
1105
-
1131
16.07
1136
-
1137
-
1200
-
1201
16.15
1215
•
1231
16.02
1301
16.02
1305
-
1306
-
1320
-
1321
16.03
1330
16.05
1331
.
1331:04
12.00
1331:30
6.03
1331:45
5.95
1332:15
5.94
1334:30
5.92
1336:30
5.90
1339
5.86
1342
5.86
1345
5.85
1351
5.86
1401
5.84
1416
5.84
1431
5.85
1723
5.95
Flow meter
reading
(gallons)
Remarks
August 2
994424.7
9* 550.0
99^690.0
995020.0
995320.0
995630.0
995860.0
996480.0
996712.0
Pump on
Measure 9.5 gpm using flow meter
Measure 9.7 gpm using flow meter
Measure 9.7 gpm using flow meter
Measure 9.6 gpm using flow meter
Measure 9.5 gpm using flow meter
Measure 9.5 gpm using flow meter
Measure 9.5 gpm using flow meter
Measure 9.5 gpm using flow meter
Measure 9.6 gpm using flow meter
Measure 9.5 gpm using flow meter
Measure 9.5 gpm using flow meter
Measure 9.5 gpm using flow meter
Pump off
Total gallons pumped Is 2,287.3 gallons
Average pumping rate is 9.5 gpm
6-229
-------
TABLE A2
WATER LEVEL DATA FOR OBSERVATION WELL S3B1
Date
(1984)
Time
(EOT)
Depth to
water
(feet)
Remarks
August 2
0743
7.85
0929
7.88
0931
_
0937
7.93
0942
7.96
0948
8.02
0957
8.01
1001
8.03
1011
8.03
1020
8.02
1030
8.02
1044
8.01
1100
8.00
1130
7.96
1200
7.95
1230
7.90
1300
7.91
1320
7.89
1331
1334
7.89
1338 : 30
7.84
1345
7.79
1350
7.77
1355
7.76
1400
7.75
1415
7.73
1430
7.74
1731
7.81
Pump on
Pump off
6-230
-------
TABLE A3
WATER LEVEL DATA FOR OBSERVATION WELL S3B3
Depth to
Date Time water
(1984) (EOT) (feet) Remarks
August 2
0836
6.60
0927
6.6 0
0931
-
0938:30
6.57
0951
6.54
1002
6.55
1013
6.48
1022
6.53
1032
6.47
1046
6.44
1102
6.42
1132
6.38
1204
6.23
1232
6.24
1302
6.23
1322
6.20
1331
1335
6.18
1340
6.19
1346
6.18
1402
6.19
1417
6.17
1432
6.18
1727
6.41
Pump on
Pump off
6-231
-------
TABLE A4
WATER LEVEL DATA FOR OBSERVATION WELL S3B4
Date
(1984)
Time
(EOT)
Depth to
water
(feet)
Remarks
August 2
0736
7.34
0836
7.19
0928
7.06
0931
-
0939
6.99
0945
6.99
0952
6.97
1003
6.91
1014
6.87
1023
6.85
1033
6.79
104-7
6.74
1103
6.67
1133
6.58
1205
6.50
1233
6.46
1303
6.44
1323
6.43
1331
-
1335:30
6.46
m 1
6.45
1347
6.45
1403
6.48
1418
6.51
1433
6.55
17 29
7.13
Pump on
Pump off
6-232
-------
TABLE A5
WATER LEVEL DATA FOR OBSERVATION WELL S3B5
Depth to
Date Time water
(1984) (EOT) (feet)
August 2
0835
6.54
0929
6.54
0931
_
0934:20
6.64
0935:10
6.66
0941
6.73
0944
6.74
0949
6.75
0953
6.75
1004
6.75
1015
6.75
1024
6.73
1034
6.74
1048
6.71
1104
6.70
1134
6.67
1206
6.63
1234
6.68
1304
6.58
1324
6.59
1331
-
1333
6.52
1337 : 30
6.42
1343
6.38
1348
6.36
1356
6.36
1404
6.35
1419
6.35
1434
6.35
1730
6.46
Remarks
Pump on
Pump off
6-233
-------
DRAWDOWN COMPUTATIONS FOR AQUIFER PUMPING TEST
Drawdowns in the pumped well and in the observation wells during the
aquifer pumping test were computed based on the water-level observations.
The drawdown computations for these wells are tabulated in the tables
which follow. In these tables the column headings have the following
meanings:
Date:
Time:
At:
At':
Depth to water:
Trend Corr.:
s;
s2/2M:
Date of reading.
Time of reading, Eastern Daylight Time
(EOT).
Time from start of pumping, in minutes.
Time since pumping stopped, in minutes.
Depth to water below the measuring
point, in feet.
A correction to account for the natural
trend in water levels. The correction
is based on the observed water-level
fluctuations in well S3B1 during the
period August 6-20, 1984.
Drawdown in the well, in feet.
Drawdown is computed by adding the
trend correction to the depth to water
measurement and substracting the depth
to water measured at approximately 0930
EDT on August 2, 1984 from this total.
A correction to account for dewatering
of the aquifer system, in feet. The
saturated thickness of the aquifer
system in the vicinity of the test
prior to pumping is represented by M.
The value for M used in these com-
putations was 27 feet. This correction
is significant only for water levels at
the pumped well.
s':
The drawdown in
the effects of
This drawdown
drawdown
zero.
the well corrected for
dewatering, in feet.
vis termed residual
whenever At' is greater than
Remarks:
Any pertinent remarks.
6-2 34
-------
TABLE B1
DRAWDOWN COMPUTATIONS FOR WELL S3B2
Date
(1984)
Time
(EDT)
At
(mln)
At1
(mln)
At
St
Depth to
water
(feet)
Trend
corr.
(feet)
s
(feet)
2
s
1H
(feet)
s'
(feet)
0930
6.03
0931
0931:28
0.47
15.77
0
9.74
1.75
7.99
0931:45
0.75
15.96
0
9.93
1.83
8.10
0932
1.00
15.98
0
9.95
1.83
8.12
0932:20
1.33
15.98
0
9.95
1.83
8.12
1932:40
1.67
15.98
0
9.95
1.83
8.12
0933
2.00
16.04
0
10.01
1.86
8.15
0933:20
2.33
16.03
0
10.00
1.86
8.14
0933:40
2.67
16.04
0
10.01
1.86
8.15
0934
3.00
16.04
0
10.01
1.86
8.15
0936
5.00
16.08
0
10.05
1.87
8.18
0937:30
6.50
16.05
0
10.02
1.86
8.16
0940
9.00
16.07
0
10.04
1.87
8.17
0943
12.0
16.09
.01
10.07
1.88
8.19
0946:30
15.5
16.08
.01
10.06
1.88
8.18
0950
19.0
16.09
.01
10.07
1.88
8.19
0955
24.0
16.05
.01
10.03
1.86
8.17
1000
29.0
16.07
.01
10.05
1.87
8.18
1012
41.0
16.09
.02
10.08
1.88
8.20
1021
50.0
16.09
.02
10.08
1.88
8.20
1031
60.0
16.08
.03
10.08
1.88
8.20
1045
74.0
16.07
.03
10.07
1.88
8.19
1101
90.0
16.08
.04
10.09
1.89
8.20
1131
120
16.07
.05
10.09
1.89
8.20
1201
150
16.15
.07
10.19
1.92
8.27
1231
180
16.02
.08
10.07
1.88
8.19
1301
210
16.02
.09
10.08
1.88
8.20
1321
230
16.03
.10
10.10
1.89
8.21
1330
239
16.05
.11
10.13
1.90
8.23
1331
240
1331:04
240
0.067
3580
12.00
.11
6.08
0.68
5.40
1331:30
240
0.50
480
6.03
.11
0.11
0
0.11
1331:45
241
0.75
321
5.95
.11
0.03
0
0.03
1332:15
242
1.25
194
5.94
.11
0.02
0
0.02
1334:30
244
3.50
69.7
5.92
.11
0.00
0
0.00
1336:30
245
5.50
44.5
5.90
.11
-0.02
0
-0.02
1339
248
8.00
31.0
5.86
.11
-0.06
0
-0.06
1342
251
11.0
22.8
5.86
.11
-0.06
0
-0.06
1345
254
14.0
18.1
5.85
.11
-0.07
0
-0.07
1351
260
20.0
13.0
5.86
.11
-0.06
0
-0.06
1401
270
30.0
9.00
5.84
.12
-0.07
0
-0.07
1416
285
45.0
6.33
5.84
.13
-0.06
0
-0.06
1431
300
60.0
5.00
5.85
.13
-0.05
0
-0.05
1723
472
232
2.03
5.95
.21
0.13
0
0.13
Remarks
August 2
Assume static water level
Pump on
Pump off
-------
TABLE B2
DRAWDOWN COMPUTATIONS FOR WELL S3B1
Date
(1984)
Time
(EDT)
At
(mln)
At'
(mln)
At
At
Depth to
water
(feet)
Trend
corr.
(feet)
s
(feet)
Remarks
August 2
0929
0931
0937
0942
0948
0957
1001
1011
1020
1030
1044
1100
1130
1200
1230
1300
1320
1331
1334
1338:30
1345
1350
1355
1400
1415
1430
1731
6.00
11.0
17.0
26.0
30.0
40.0
49.0
59.0
73.0
89.0
119
149
179
209
229
240
243
247
254
259
264
269
284
299
480
3.00
7.50
14.0
19.0
24.0
29.0
44.0
59.0
240
81.0
32.9
18.1
13.6
11.0
9.27
6.45
5.07
2.00
7.88
7.93
7.96
8.02
8.01
8.03
8.03
8.02
8.02
8.01
8.00
7.96
7.95
7.90
7.91
7.89
7.89
7.84
7.79
7.77
7.76
7.75
7.73
7.74
7.81
0
0.01
0.01
0.01
0.01
0.02
0.02
0.03
0.03
0.04
0.05
0.07
0.08
0.09
0.10
0.11
0.11
0.11
0.11
0.12
0.12
0.12
0.13
0.21
0.05
0.09
0.15
0.14
0.16
0.17
0.16
0.17
0.16
0.16
0.12
0.13
0.10
0.12
0.11
0.12
0.07
0.02
0.00
0.00
-0.01
-0.03
-0.01
0.14
Assume static water level
Pump on
Pump off
-------
TABLE B3
DRAWDOWN COMPUTATIONS FOR WELL S3B3
Depth to Trend
Date Time At At' At water corr. s
(1984) (EDT) (win) (win) Tit (feet) (feet) (feet) Remarks
August 2 0927 6.60 Assume static water level
Pump on
0927
6.60
0931
0938:30
7.50
6.57
0
-0.03
0951
20.0
6.54
0.01
-0.05
1002
31.0
6.55
0.01
-0.04
1013
42.0
6.48
0.02
-0.10
1022
51.0
6.53
0.02
-0.05
1032
61.0
6.47
0.03
-0.10
1046
75.0
6.44
0.03
-0.13
1102
91.0
6.42
0.04
-0.14
1132
121
6.38
0.05
-0.17
1204
153
6.23
0.07
-0.30
1232
181
6.24
0.08
-0.28
1302
211
6.23
0.09
-0.28
1322
231
6.20
0.10
-0.30
1331
240
1335
244
4.00
61.0
6.18
0.11
-0.31
1340
249
9.00
27.7
6.19
0.11
-0.30
1346
255
15.0
17.0
6.18
0.11
-0.31
1402
271
31.0
8.74
6.19
0.12
-0.29
1417
266
46.0
6.22
6.17
0.13
-0.30
1432
301
61.0
4.93
6.18
0.13
-0.29
1727
476
236
2.02
6.41
0.21
0.02
Pump off
-------
TABLE B4
DRAWDOWN COMMUTATIONS FOR WELL S384
Date
(1984)
Depth to
Trend
Time
At
At*
At
water
corr.
s
(EDT)
(min)
(mln)
St
(feet)
(feet)
(feet)
0928
7.06
0931
0939
8.00
6.99
0
-0.07
0945
14.0
6.99
0.01
-0.06
0952
21.0
6.97
0.01
-0.08
1003
32.0
6.91
0.01
-0.14
1014
43.0
6.87
0.02
-0.17
1023
52.0
6.85
0.02
-0.19
1033
62.0
6.79
0.03
-0.24
1047
76.0
6.74
0.03
-0.29
1103
92.0
6.67
0.04
-0.35
1133
122
6.58
0.05
-0.43
1205
154
6.50
0.07
-0.49
1233
162
6.46
0.08
-0.52
1303
212
6.44
0.09
-0.53
1323
232
6.43
0.10
-0.53
1331
240
1335:30
244
4.5
54.2
6.46
0.11
-0.40
1341
250
10.0
25.0
6.45
0.11
-0.50
1347
256
16.0
16.0
6.45
0.11
-0.50
1403
272
32.0
8.50
6.48
0.12
-0.46
1418
287
47.0
6.11
6.51
0.13
-0.42
1433
302
62.0
4.87
6.55
0.13
-0.38
1729
478
238
2.01
7.13
0.21
0.28
Remarks
August 2
Assume static water level
Pump on
Pump off
-------
TABLE B5
DRAWDOWN COMPUTATIONS FOR WELL S3B5
Date
(1984)
Trend
Time
At
At'
At
water
corr.
s
(EOT)
(mln)
(mln)
St
(feet)
(feet)
(feet)
0929
6.54
0931
0934:20
3.33
6.64
0
0.10
0935:10
4.17
6.66
0
0.12
0941
10.0
6.73
0
0.19
0944
13.0
6.74
0.01
0.21
0949
18.0
6.75
0.01
0.22
0953
22.0
6.75
0.01
0.22
1004
33.0
6.75
0.01
0.22
1015
44.0
6.75
0.02
0.23
1024
53.0
6.73
0.02
0.21
1034
63.0
6.74
0.03
0.23
1048
77.0
6.71
0.03
0.20
1104
93.0
6.70
0.04
0.20
1134
123
6.67
0.05
0.18
1206
155
6.63
0.07
0.16
1234
183
6.68
0.08
0.22
1304
213
6.58
0.09
0.13
1324
233
6.59
0.10
0.15
1331
240
1333
242
2.00
121
6.52
0.11
0.09
1337:30
246
6.50
37.8
6.42
0.11
-0.01
1343
252
12.0
21.0
6.38
0.11
-0.05
1348
257
17.0
15.1
6.36
0.11
-0.07
1356
265
25.0
10.6
6.36
0.12
-0.06
1404
273
33.0
8.27
6.35
0.12
-0.07
1419
288
48.0
6.00
6.35
0.13
-0.06
1434
303
63.0
4.81
6.35
0.13
-0.06
1730
479
239
2.00
6.46
0.21
0.13
Remarks
August 2
Assume static water level
Pump on
Pump off
-------
AQUIFER PUMPING TEST ANALYSIS
Water-level data for the pumped well and for observation wells S3B1
and S3B5 were used to compute the hydraulic properties of the uncon-
solidated deposits. The modified Theis nonequilibrium analysis and
water-level data for the the pumped well were used to compute transmissi-
vity. Type curves developed by Stallman (Lohman, 1972) and water-level
data for observation wells S3B1 and S3B5 were used to compute transmissi-
vity and storage coefficient. Additionally, vertical hydraulic conduc-
tivity for the unconsolidated deposits was computed using water level
data from observation well S3B1.
Drawdowns observed during early times in the aquifer pumping test
were used for the analysis. Changes in water levels caused by the ocean
tide began to strongly influence changes in drawdown due to pumping after
10 to 20 minutes of pumping.
The form of the modified Theis nonequilibrium analysis formula used
for the computations is
The variables in the above equation have the following meaning:
T = transmissivity, in gallons per day per foot;
Q = average pumping rate, in gallons per minute; and
as = change in drawdown over one log-cycle for a semi-log plot of
Type curves developed by Stallman (Lohman, 1972) for a pumping well
penetrating the bottom three-tenths of a water-table aquifer were used
for matching the drawdowns observed in monitoring wells S3B1 and S3B5.
The forms of the equations used in the computations are
264Q
T
AS
time and drawdown.
1440QW(Ug *)
where: 1 = Tt
Ub 10,770r2 S
and
6-240
-------
The variables in the above equations that have not previously been
defined have the following meanings:
s = drawdown in the observation well at the match point,
in feet;
W(UB, *) = for observation well S3B5, the well function for a
pumping well penetrating the bottom three-tenths of a
water-table aquifer and an observation well completed
near the aquifer base, no dimensions;
W(Ug,i') = for observation well S3B1, the well function for a
pumping well penetrating the bottom three-tenths of a
water-table aquifer and an observation well completed
near the water table, no dimensions;
r = distance from pumping well to observation well, in
feet;
S = storage coefficient, no dimensions;
t = time at the match point, in minutes;
Kv = vertical hydraulic conductivity of the aquifer, in
gallons per day per foot squared; and
b = initial aquifer saturated thickness, in feet.
The parameters W(Ub,V ), Ub^ , S and T were determined bv matching log-
log plots of time and drawdown data to the type curves for W(Ub^ ) and
1/Ub developed by Stallman.
The data plots and data analyses are presented in Figures CI, C2 and
C3.
6-241
-------
7A
a\
i
NJ
to
8.0
c
*
o
TJ
*
8.3
8.4
8.5
a
f —»
)-
•
T = 264Q = (264X9.5)
AS 0.10
T = 26,100flpd/ft.
1 -
—
•
¦«-, •
•
TsSs,|||^ • •
• _
• • • * —
-
—
•
Q1
1 10
Time since pumping began (minutes)
100
Figure C-l. Modified Theis nonequilibrium analysis using data from well S3B2.
-------
~ 1.0
0.1
0.01
MatchpoinT
w
W(UB>)=
sT
1440Q
Tt
= 1.0
UB 10,770r2S
= 1.0
J i ' f » t'll
' i »iii
1 1—i II 11IJ
10 100
Time since pumping began (minutes)
j i i i i 11
T =
1440Q (1440X9.5)
s
1.15
T = 11,900gpd/f t.
S =
Tt _ (11.900X3.0)
10,770r2 (10.770X10.8)2
S = 0.028
1000
Figure C-2. Nonequilibrium analysis using data from well S3B5.
-------
I
to
1.0
Matchpoint
© H
c
S
o
T3
*
at
0.1
WO^,*) =
ST
1440Q
Tt
= 1.0
Ub 10,770r2S
= 1.0
*=r(—) = 0.33
» \ bT /
T =
T =
S =
1440Q = (1440X9.5)
s 1.00
13,700 gpd/ft.
Tt (13,700X30)
10,770r2 (10,770)(9.0)J
S= 0.047
„ (0.33)2bT_ (0.33)2(27)( 13,700)
*v :
(9.0)'
Kv = 497gpd/ft.
.01
1 '
i i i i 111
¦ ¦ ¦
^1
* ¦ ¦ ¦ ¦ ¦
10 100
Time since pumping began (minutes)
1000
Figure C-3. Nonequilibrium analysis using data from well S3B7
-------
APPENDIX D
6-245
-------
ELEVATION DATA
The mean sea level elevation of the water-level measuring point on
each monitoring well and ocean tidal guage well and the mean sea eleva-
tion of the zero elevation for each sound tidal guage were determined.
These data are tabulated in the tables that follow. In these tables, the
column headings have the following meaning:
Well site:
The well site identifier.
Well ID:
Measuring point
elevation:
Land surface
elevation:
Bench mark
elevation:
The well identifier.
The elevation of the measuring point on
the well, in feet mean sea level.
The elevation of land surface at the
well, in feet mean sea level.
The elevation of the bench mark
established in the well site vicinity,
in feet mean sea level.
Bench mark
description:
A general description of the bench mark
established at the well site and the
bench mark location.
6-246
-------
TABLE 1
SUMMARY OF ELEVATION DATA FOR KILL DEVIL HILLS
Weil
site
Well
ID
Measuring
point
elevation
(MSL)
Land
surface
elevation
(MSL)
Bench
mark
elevation
(MSL)
Bench mark
description
K1A
K1A1
11.897
11.1
13.443
K1A2
11.767
10.9
K1A3
11.890
10.0
K1B
K1B1
10.380
9.7
9.367
K1C
K1C1
9.607
10.0
9.961
K1C4
9.727
10.0
K1C5
9.614
9.9
KID
K1D1
10.032
10.2
12.028
K IE
KIE1
5.415
4.6
6.182
K1E2
5.213
4.4
KIE3
5.809
4.9
K2A
K2A1
12.470
11.3
13.609
K2A2
12.044
10.9
K2A3
12.186
11.1
K2B
K2B1
9.258
8.3
8.779
K2B2
9.200
9.0
K2B3
8.739
7.8
K2C
K2CI
9.380
9.5
9.668
K2C2
9.380
9.7
K2C3
9.310
9.6
K2C4
8.977
9.3
K2D
K2D1
11.798
12.1
13.621
K2D2
12.009
12.3
K2D3
12.037
12.3
K2E
K2E1
5.318
4.3
6.365
K2E2
5.177
4.3
K2EJ
5.460
4.4
K3A
K3A1
13.584
12.8
13.215
K3A2
13.525
13.0
K3A28
12.941
11.9
K3A3B
13.165
12.2
K3B
K3BI
10.288
9.6
9.098
K3C
K3CI
13.965
12.9
4.585
K3D
K301
15.737
13.9
16.332
K3D2
17.328
13.9
K3D3
14.675
13.5
Top of concrete right-of-
way monument on southwest
corner of Chowan Avenue
and Business Route 158.
Top of concrete right-of-
way monument on southeast
corner of Chowan Avenue
and Bypass Route 158.
Nail in side of wooden
post at well site.
Nail in top of wooden post
at well site.
Spike in maple tree about
20 feet west of well site.
Nail in top of guard post
at well site.
Top of concrete right-of-
way monument ori southeast
corner of 5th street and
Bypass Route 158.
Nail in stop sign post on
Wilbur Court at southeast
corner of intersection
with 5th street.
Nail in top of wooden post
at well site.
Nail in top of wooden post
at well site.
Nail in north side of
wooden ramp at base of
first railing post.
Nail in pole VPCo D153 on
southeast corner of Ocean
Bay Boulevard and Mustian
Street.
Top nail in pole 14 along
fence.
Nail in top of third guard
post south of private road
entrance.
6-247
-------
TABLE 1
(continued)
SUMMARY OF ELEVATION DATA FOR KILL OEVIL HILLS
Weil
site
Well
ID
Measuring
point
elevation
(HSL)
Land
surface
elevation
(MSL)
Bench
mark
elevation
(HSL)
Bench mark
description
K3E
K3F
K3E1
K3F1
K3G K3G1
K3G2
K3G3
Ocean gauge
Sound gauge
13.040
12.946
6.469
6.52*
6.480
16.75
-0.25d
12.2
11.4
5.4
5.3
5.1
14.645 Nail in wooden post about
15 feet south of fence
line and about 60 feet
north of well site.
12.407 Nail in guard post about
20 feet east of weLl site.
7.813 Nail in top of wooden post
at well site.
17.341 Mark on deck immediately
above stilling well pipe.
6.534 Top of post on south pier.
aEievation of zero reading on staff gauge.
6-248
-------
TABLE 2
SUMMARY OF ELEVATION DATA FOR ATLANTIC BEACH
Well
site
Well
ID
Measuring
point
elevation
(MSL)
Land
surface
elevation
(MSL)
Bench
mark
elevation
(MSL)
Bench mark
description
A1A
A1A1
A1A3
10.675
10.619
9.8
9.9
10.668
Nail in top of west quard
post at Dunes Avenue and
Boardwalk Avenue.
A1B
A1B1
A1B3
8.748
8.683
8.0
8.0
8.730
Nail in side of
"Community Watch" siqn at
well site.
Air
A1C1
A1C3
11.133
10.984
10.3
10.0
12.305
Top of iron pipe next to
utility pole on east side
of Dunes Avenue across
from well site.
A1P
A1D1
A1D2
AW3
4.976
4.823
5.055
5.3
5.1
5.4
6.969
Nail in top of wooden post
at well site.
A2A
A2A1
A2A3
A2A4
10.120
10.081
9.921
11.3
11.3
11.3
10.632
Nail in top of wooden post
at well site.
A2B
A2B1
A2B3
A2B4
6.671
6.602
6.752
7.0
6.9
7.0
8.643
Nail in top of wooden post
at well site.
A2C
A2C1
A2C3
A2C4
4.445
4.610
4.559
4.9
4.9
4.9
6.382
Nail in top of wooden post
at well site.
Ocean
qauqe
16.89
17.935
Mark on deck immediately
above stillinq well pipe.
Sound
qauqe
-1.863
6.121
Top of post at staff qauqe
location.
Elevation of zero readina on staff qauqe.
6-249
-------
TABLE 3
SUMMARY OF ELEVATION DATA FOR PINE KNOLL SHORES
Well
site
Well
ID
Measuring
point
elevation
(MSL)
Land
surface
elevation
(MSL)
Bench
mark
elevation
(MSL)
Bench mark
description
P1A
P1A1
P1A2
P1A3
15.250
15.281
15.316
14.0
14.3
14.0
16.162
Nail in top of wooden post
at well site.
P1R
P1B1
13.173
12.3
16.901
Top of concrete right-of-
way monument on southwest
corner of Yaupon Road and
Salter Path Road.
P1C
P1C1
P1C2
P1C3
P1C4
7.5*3
7.429
7.552
7.553
7.8
7.8
7.9
7.9
9.545
Nail in top of wooden post
at well site.
P1D
P1D1
10.951
11.4
13.184
Top of iron pipe between
127 and 129 Yaupon Road.
PIE
PtEl
P1D2
P1E3
9.327
9.385
9.290
8.2
8.2
8.3
8.971
Nail in stop sign post at
intersection of Yaupon
Road and Oakleaf Drive.
P2A
P2A1
P2A2
P2A3
14.799
14.921
15.111
15.2
15.3
15.4
15.370
Nail in edge of bituminous
parking lot at well site.
P2B
P2B1
11.550
10.7
12.091
Top of concrete right-of-
way monument on northwest
corner of Pine Knoll
Boulevard and Salter Path
Road.
P2C
P2C1
P2C2
P2C3
P2C4
9.380
8.426
7.911
7.811
6.9
6.9
6.9
7.0
7.207
Nail in edge of road about
14 feet east of well site.
P2D
P2D1
8.965
8.1
7.758
Nail in utility pole on
southeast corner of Pine
Knoll Boulevard and Ramsey
Drive.
P2E
P2E1
P2E2
P2E3
7.158
7.069
7.164
6.4
6.0
6.3
5.812
Top of manhole frame on
McGinnis Drive near well
site.
6-250
-------
TABLE 4
SUMMARY OF ELEVATION DATA FOR SURF CITY
Well
site
Well
ID
Measuring
(>oint
elevation
(Ma)
Land
surface
elevation
(MSL)
Bench
mark
elevation
(MSL)
Bench mark
description
S1A
S1A1
SIA2
S1A3
9.334
9.079
9.442
9.7
9.6
9.6
10.337
Nail in pole near ramp
leading to beach at Pender
Avenue and Shore Drive.
SIB
S1B1
S1B2
S1B3
5.575
5.369
>.262
5.8
5.7
5.6
6.880
Naii in utility pole at
motel on corner of Pender
Avenue and New River
Drive.
S3A
S3A1
S3A2
S3A3
12.260
12.035
11.922
11.7
11.7
11.5
11.692
Top of concrete monument
on southeast corner of
Shore Drive and Goldsboro
Avenue.
S3B
S3B1
S3B2
S3B3
S3B4
S3B5
9.948
7.785
7.819
8.147
8.323
8.6
8.1
8.2
8.6
8.7
9.457
Naii in pole NA-6 on
corner of Goldsboro Avenue
and Topsail Avenue.
S3C
S3C1
S3C2
S3C3
4.828
5.304
5.585
3.7
4.0
4.3
5.457
Nail in pole at Surf City
rescue squad building.
Ocean
gauge
22.005
Sound
gauge
-0.50a
Elevation of zero reading on staff gauge.
6-251
-------
APPENDIX E
6-253
-------
WATER LEVEL DATA
Ground-water level data were collected periodically in each study
area, as were water-level data for the ocean and sound at each area.
These data are tabulated in the tables that follow along with water-level
elevations computed from the data. In these tables, the column headinys
have the following meaning:
Well ID (monitoring wells only): The well identifier.
Measurement date:
Measurement time:
Depth to water from measuring
points (monitoring wells and
ocean tidal gauges):
Staff gauge reading (sound
gauges only):
The date of the measurement.
The time of the measurement.
The distance, in feet, from the
measuring point to the water
surface.
The water level, in feet, read
directly from a staff gauge
graduated in 0.02 foot incre-
ments.
Water level elevation:
The mean sea level elevation of
the water surface computed from
the data.
6-254
-------
WATER-LEVEL DATA
FOR
KILL DEVIL HILLS
6-255
-------
TABLE 1
ATLANTIC OCEAN TIDAL MEASUREMENTS
AT KILL DEVIL HILLS
Depth to water
from
Measurement
Measurement
measuring point
Water level elevation
Date
Time
(ft)
(MSL)
10 Oul 84
1210
-1.2a
17 Aug
0437
-1.0a
1058
1.9d
1711
-0.7a
2)07
1.6a
0514
-0.9a
1140
1.9a
17 Sep
1720
15.31
1.44
18 Sep
0758
15.87
0.88
0858
15.71
1.04
19 Oct
1712
13.99
2.76
20 Oct
0856
16.81
-0.06
21 Oct
0821
16.31
0.62
12 Nov
1237
15.01
1.74
1626
16.81
-0.06
13 Nov
0704
15.74
1.01
0824
14.21
2.54
10 Oec
1353
-1.3d
11 Oec
0807a
1,8a
15 Can 85
1446
1.5a
9 Feb
1330
17.39
-0.64
1610
18.83
-2.08
2040
15.64
1.11
10 Feb
0018
15.51
1.24
0433
18.16
-1.41
6 Mar
1505
-0.7d
9 Apr
0911
1.0d
6 May
1622
-0.5a
a
Estimated from
tidal tables (NOAA,
1985).
6-256
-------
TABLE 2
ALBEMARLE SOUND TIDAL fCASUREMENTS
AT KILL DEVIL HILLS
Measurement
Date
Measurement
Time
Staff gauge
reading
(ft)
Water level elt
(MSL)
11 3ul 84
1440
1.34
1.09
17 Aug
0811
1.28
1.03
1125
1.23
0.98
1531
1.21
0.96
2104
1.21
0.96
18 Aug
0037
1.30
1.05
0432
1.39
1.14
17 Sep
1730
0.56
0.31
18 Sep
0750
0.70
0.45
0908
0.62
0.37
19 Oct
1722
1.84
1.59
20 Oct
0948
1.92
1.67
21 Oct
0920
1.92
1.67
12 Nov
1249
1.55
1.30
1618
1.48
1.23
13 Nov
07 H
1.40
1.15
0834
1.50
1.25
10 Dec
1357
0.88
0.63
11 Dec
0845
0.86
0.61
1104
0.92
0.67
15 Dan 83
1410
1.24
0.99
1550
1.18
0.93
9 Feb
093 2
0.91
0.66
1434
0.96
0.71
1712
0.75
0.50
2205
0.65
0.40
10 Feb
0139
0.91
0.66
0620
0.60
0.35
6 Mar
1409
0.70
0.45
1639
0.53
0.28
9 Apr
0853
1.55
1.30
1002
1.50
1.25
10 Apr
0806
0.40
0.15
1120
0.30
0.05
6 May
1551
1.30
1.07
1830
1.35
1.10
6-257
-------
TABLE 3
GROUND-WATER LEVEL MEASUREMENTS
AT KILL DEVIL HILLS
Depth to water
from
Weil Measurement Measurement measuring point Water level elevation
I.D. Date T.'jie (ft) (MSL)
9 Dul 84
1100
8.88
3.02
17 Aug
0655
8.88
3.02
1049
8.91
2.99
1458
8.90
3.00
2017
8.86
3.04
2359
8.92
2.98
18 Aug
0359
8.87
3.03
18 Sep
0852
6.69
5.21
0926
6.69
5.21
20 Oct
0904
4.77
7.13
0956
4.78
7.12
13 Nov
0739
6.38
5.52
0812
6.38
5.52
11 Dec
0812
8.20
3.70
0959
8.20
3.70
15 Oan 8b
1345
8.14
3.76
1535
8.15
3.75
9 Feb
0830
7.83
4.07
1345
7.84
4.0 6
1618
7.85
4.05
2050
7.88
4.02
10 Feb
0027
7.94
3.96
0440
7.90
4.00
6 Mar
1336
8.37
3.53
1617
8.35
3.55
10 Apr
0703
8.32
).58
1044
8.34
3.56
6 May
1415
7.95
3.95
1742
8.01
3.89
9 Oul 84
1110
8.72
J.05
17 Aug
0650
8.72
J.05
1051
8.76
3.01
1500
8.74
3.03
2019
8.73
3.04
18 Aug
0002
8.73
3.04
0401
8.72
3.05
18 Sep
0851
6.55
5.22
0925
6.54
5.23
20 Oct
0905
4.66
7.11
0957
4.67
7.10
13 Nov
0739
6.23
5.54
0813
6.24
5.53
11 Dec
0813
8.03
3.74
1000
8.03
3.74
15 Oan 83
1345
8.00
3.77
1535
8.00
3.77
9 Feb
0831
7.67
4.10
1346
7.70
4.07
1619
7.73
4.04
2052
7.73
4.04
10 Feb
0028
7.78
3.99
0441
7.76
4.01
6 Mar
1336
8.22
3.55
1616
8.21
3.56
10 Apr
0704
8.18
3.59
1045
8.20
3.57
6 May
1416
7.84
3.86
1742
7.89
3.88
6-258
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT KILL DEVIL HILLS
Depth to water
from
Well
Measurement
Measurement
measuring point
Water level elevation
l.D.
Date
Time
(ft)
(MSL)
KIA3
9 3ul 84
1115
8.83
3.06
17 Aug
0655
8.81
3.08
1052
8.8 2
3.07
1501
8.83
3.06
2020
8.80
3.09
18 Aug
0003
8.81
3.08
0358
8.88
3.01
18 Sep
0850
6.63
5.26
0924
6.64
5.25
20 Oct
0905
4.80
7.09
0957
4.81
7.08
13 Nov
0740
6.35
5.54
0814
6.34
5.55
11 Dec
0814
8.10
3.79
1001
8.10
3.79
15 Dan 83
1346
8.07
3.82
1535
8.09
3.80
9 F eb
0832
7.72
4.17
1347
7.81
4.08
1620
7.81
4.08
2054
7.87
4.02
10 Feb
0030
7.87
4.02
0443
7.87
4.02
6 Mar
1335
8.32
3.57
1615
8.31
3.58
10 Apr
0705
8.28
3.61
1045
8.31
3.58
6 May
1417
7.97
3.92
1743
8.01
3.88
K1B1
10 Jul 84
1050
4.63
5.75
17 Aug
0706
4.85
5.53
1058
4.86
5.52
1509
4.87
5.51
2028
4.87
5.51
18 Aug
0010
4.89
5.49
0408
4.91
5.47
18 Sep
0846
3.29
7.09
0922
3.30
7.08
20 Oct
0916
4.06
6.32
1003
4.06
6.32
13 Nov
0734
3.99
6.39
0808
4.00
6.38
11 Dec
0820
4.27
6.11
1013
4.28
6.10
15 Jan 85
1350
4.80
5.58
1540
4.82
5.56
9 Feb
0837
4.32
6.06
1350
4.33
6.05
1625
4.34
6.04
2058
4.38
6.00
10 Feb
0034
4.39
5.99
0501
4.37
6.01
6 Mar
1342
4.52
5.96
1621
4.43
5.95
10 Apr
0723
4.87
5.51
1046
4.88
5.50
6 May
1427
5.29
5.09
1748
5.28
5.10
6-259
-------
TABLE 3
(continued)
GROUND-WATER LEVa MEASUREMENTS
AT KILL DEVIL HILLS
Depth to water
from
Well
Measurement
Measurement
measuring
l.D.
Date
Time
(ft)
K1C1
9 3ul 84
1500
3.38
17 Aug
0703
3.73
1106
3.73
1512
3.75
2035
3.75
18 Aug
0018
3.75
0413
3.76
18 Sep
0841
2.26
0918
2.26
20 Oct
0921
3.18
1007
3.18
13 Nov
0730
3.33
0759
3.34
It Dec
0824
3.45
1019
3.45
15 Jan 85
1355
3.98
1543
3.98
9 Feb
0841
3.42
1353
3.41
1628
3.44
2100
3.44
10 Feb
0036
3.45
0506
3.43
6 Mar
1350
3.36
1625
3.36
10 Apr
0731
3.81
1050
3.81
6 May
1433
4.29
1750
4.29
KIC4
9 Oul 84
1500
3.70
17 Aug
0704
4.05
1102
4.05
1513
4.06
2037
4.06
18 Aug
0014
4.08
0414
4.09
18 Sep
0842
2.55
0919
2.55
20 Oct
0921
3.49
1007
3.49
1 i Nov
0731
3.63
0759
3.64
11 Dec
0825
3.77
1020
3.77
15 3an 85
1355
4.30
1543
4.29
9 Feb
0841
3.42
1J54
3.77
1629
3.78
2102
3.77
10 Feb
0038
3.80
0507
3.80
6 Mar
1348
3.70
1624
3.70
10 Apr
0732
4.15
1051
4.16
6 May
1434
4.60
1751
4.61
Water level elevation
(MSL)
6.23
5.88
5.88
5.86
5.86
5.86
5.85
7.35
7.35
6.43
6.43
6.28
6.27
6.16
6.16
5.63
5.63
6.19
6.20
6.17
6.17
6.16
6.18
6.25
6.25
5.80
5.80
5.32
5.32
6.03
5.68
5.68
5.67
5.67
5.65
5.64
7.18
7.18
6.24
6.24
6.10
6.09
5.96
5.96
5.43
5.44
6.19
5.96
5.95
5.96
5.93
5.93
6.03
6.03
5.58
5.57
5.13
5.12
6-260
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT KILL DEVIL HILLS
Depth to water
from
Well
I.D.
Measurement
Date
Measurement
Time
measuring point
(ft)
Water level elevation
(MSL)
K1C5
? 3ui W
1501
3.60
6.01
17 Aug
0705
3.94
5.67
1105
3.94
5.67
1515
3.96
5.65
2040
3.95
5.66
18 Aug
0016
3.97
5.64
0416
3.98
5.63
IS Sep
0844
2.44
7.17
0920
2.44
7.17
20 Oct
0922
3.38
6.23
1008
3.38
6.23
13 Nov
0731
3.53
6.08
0800
3.52
6.09
11 Dec
0826
3.66
5.95
1020
3.66
5.95
15 Jan 85
1356
4.18
5.43
1543
4.18
5.43
9 Feb
0843
3.67
5.94
1355
3.67
5.94
1630
3.68
5.93
2103
3.69
5.92
10 Feb
0040
3.72
5.89
0509
3.70
5.91
6 Mar
1349
3.60
6.01
1625
3.60
6.01
10 Apr
0733
4.03
5.58
1052
4.04
5.57
6 May
1434
4.49
5.12
1751
4.48
5.13
KID1
10 3ul 84
1110
5.03
5.00
17 Aug
0716
5.12
4.91
1109
5.13
4.90
1518
5.12
4.91
2047
5.13
4.90
18 Aug
0022
5.15
4.88
0420
5.17
4.86
18 Sep
0836
3.69
6.34
0916
3.69
6.34
20 Oct
0931
4.69
5.34
1011
4.69
5.34
13 Nov
0725
5.02
5.01
0754
4.99
5.04
11 Dec
0832
5.09
4.94
1030
5.09
4.94
15 Jan 85
1400
5.51
4.52
1545
5.51
4.52
9 Feb
0846
5.06
4.97
1358
5.07
4.96
1633
5.06
4.97
2107
5.38
4.65
10 Feb
0040
5.09
4.94
0519
5.05
4.98
6 Mar
1359
4.98
5.05
1629
4.98
5.05
10 Apr
0742
5.37
4.66
1055
5.30
4.73
6 May
1440
5.66
4.37
1756
5.67
4.36
6-261
-------
TABLE 3
(continued)
GROUND-WATER LEVEL fCASUREMENTS
AT KILL DEVIL HILLS
Depth to water
from
Well
Measurement
Measurement
measuring point
Water level elevation
l.D.
Date
Time
(ft)
(MSL)
KIE1
10 3ul 84
1130
3.21
2.21
17 Aug
0721
2.93
2.49
1114
3.08
2.34
1523
3.21
2.21
2034
3.11
2.31
18 Aug
0028
3.03
2.39
0424
3.00
2.42
18 Sep
0832
1.99
3.43
0912
1.96
3.46
20 Oct
0935
2.14
3.28
1015
2.15
3.27
13 Nov
0720
2.01
3.41
0746
2.00
3.42
11 Dec
0837
2.03
3.39
1033
2.04
3.38
15 Jan 85
1403
2.20
3.22
1548
2.21
3.21
9 Feb
0849
2.05
3.37
1401
1.91
3.51
1636
1.91
3.51
2111
1.99
3.43
10 Feb
0046
2.01
3.41
0522
2.03
3.39
6 Mar
1403
2.11
3.31
1634
2.12
3.30
10 Apr
0748
2.58
2.84
1058
2.57
2.85
6 May
1445
2.95
2.47
1759
2.97
2.45
K1E2
10 Oui 84
1135
2.65
2.56
17 Aug
0723
2.74
2.47
1116
2.81
2.40
1324
2.86
2.35
2055
2.84
2.37
18 Aug
0030
2.81
2.40
0426
2.76
2.45
18 Sep
0833
2.49
2.72
0913
2.52
2.69
20 Oct
0935
2.11
3.10
1016
2.12
3.09
13 Nov
0720
2.56
2.65
0746
2.53
2.68
11 Dec
0838
2.88
2.33
1036
2.87
2.34
13 3dn 83
1403
2.70
2.31
1348
2.81
2.40
9 Feb
0850
2.83
2.38
1402
2.85
2.36
2113
3.00
2.21
10 F eb
0048
3.05
2.16
0523
3.04
2.17
6 Mar
1404
3.11
2.10
1635
3.16
2.05
10 Apr
0748
3.23
1.98
1059
3.31
1.90
6 May
1446
2.86
2.35
1759
2.96
2.25
6-262
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT KILL DEVIL HILLS
Depth to water
from
Well
Measurement
Measurement
measuring
I.D.
Date
Time
(ft)
KIE3
10 3ul 84
1125
3.26
17 Aug
0720
3.33
1113
3.40
1522
3.46
2057
3.42
18 Aug
0026
3.40
0427
3.33
18 Sep
0831
J.09
0911
3.10
20 Oct
0936
2.70
1016
2.71
13 Nov
0721
3.14
0746
3.10
11 Dec
0838
3.47
1037
3.46
15 3an 85
1404
3.26
1548
3.41
9 Feb
0851
3.40
1402
3.44
1638
3.45
2115
3.56
10 Feb
0050
3.61
0524
3.63
6 Mar
1402
3.68
1633
3.73
10 Apr
0749
3.80
1100
3.89
6 May
1447
J.45
1800
3.44
K2A1
10 3ul 84
1435
10.03
17 Aug
0745
10.10
1051
10.13
1453
10.02
2200
10.10
18 Aug
0125
10.03
0515
10.03
18 Sep
0712
8.21
0803
8.23
21 Oct
0831
6.57
0927
6.62
12 Nov
1438
7.27
1516
7.28
11 Dec
092 J
9.44
1156
9.37
15 Dan 85
1438
9.25
1613
9.21
9 Feb
0859
8.26
1408
8.22
1644
8.30
2127
8.40
10 Feb
0055
8.26
0531
5.65
6 Mar
1444
9.24
1706
9.27
9 Apr
0826
9.26
0936
9.28
6 May
1500
8.66
1806
8.80
Water level elevation
(MSL)
2.55
2.48
2.41
2.35
2.39
2.41
2.48
2.72
2.71
3.11
3.10
2.67
2.71
2.34
2.35
2.55
2.40
2.41
2.37
2.36
2.25
2.20
2.18
2.13
1:81
1.92
2.36
2.37
2.44
2.37
2.34
2.45
2.37
2.44
2.44
4.26
4.24
5.90
5.85
5.20
5.19
3.03
3.10
3.22
3.26
4.21
4.25
4.17
4.07
4.21
6.82
3.23
3.20
3.21
3.19
3.81
3.67
6-263
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT KILL DEVIL HILLS
Depth to water
from
Well
Measurement
Measurement
measuring
l.D.
Date
Time
(ft)
K2A2
10 Jul 84
1438
9.64
17 Aug
0744
9.69
1049
9.72
1455
9.60
2201
9.68
18 Aug
0124
9.62
0517
9.63
18 Sep
0714
7.82
0804
7.85
2) Oct
0832
6.15
0927
6.22
12 Nov
1437
6.82
1515
6.87
11 Dec
0924
8.99
1157
8.82
15 Jan 85
1438
8.80
1614
8.75
9 Feb
0900
7.93
1408
7.86
1645
7.97
2129
8.06
10 Feb
0057
7.90
0533
7.93
6 Mar
1443
8.89
1707
8.89
9 Apr
0827
8.92
0937
8.93
6 May
1501
8.39
1807
8.51
K2A3
10 Jul 84
1516
9.77
17 Aug
0742
9.79
1047
9.01
1456
9.23
2203
9.30
18 Aug
0123
9.10
0725
9.85
18 Sep
0716
8.69
0805
8.66
21 Oct
0832
8.09
0928
8.40
12 Nov
1435
8.45
1515
8.56
11 Dec
0924
8.31
1158
8.80
15 Jan 85
1439
8.58
1614
8.70
9 Feb
0901
8.35
1410
9.14
1646
9.60
2131
8.30
10 Feb
0059
8.38
0535
9.33
6 Mar
1446
9.56
1709
8.70
9 Apr
0828
9.32
0938
8.97
6 May
1502
10.18
1807
9.62
Water level elevation
(MSL)
2.40
2.35
2.32
2.44
2.36
2.42
2.41
4.22
4.19
5.89
5.82
5.22
5.17
3.05
3.22
3.24
3.29
4.11
4.18
4.07
3.98
4.14
4.11
3.15
3.15
3.12
3.11
3.65
3.53
2.42
2.40
3.18
2.96
2.89
3.09
2.34
3.50
3.53
4.10
3.79
3.74
3.63
3.88
3.39
3.61
3.49
3.84
3.05
2.59
3.89
3.81
2.86
2.63
3.49
2.87
3.22
2.01
2.57
6-264
-------
TABLE 3
(continued)
GROUND-WATER LEVEL FCASUREMENTS
AT KILL DEVIL HILLS
Depth to water
from
Weil
Measurement
Measurement
measuring
I.D.
Date
Time
1ft)
K2B1
10 3ui 84
1427
4.76
17 Aug
0735
4.96
1059
4.96
1505
4.97
2149
4.98
18 Aug
0114
4.98
0505
4.98
18 Sep
0723
3.44
0810
3.44
21 Oct
0844
3.79
1011
3.79
12 Nov
1443
3.64
1531
3.65
11 Dec
0916
4.13
1147
4.13
15 Oan 85
1434
4.48
1610
4.48
9 Feb
0905
4.11
1414
4.11
1650
4.31
2134
4.14
10 Feb
0105
4.14
0548
4.15
6 Mar
1436
4.27
1702
4.29
9 Apr
0834
4.67
0942
4.67
6 May
1511
5.02
1810
5.03
K2B2
10 Jul 84
1423
4.68
17 Aug
0734
4.89
1101
4.88
1506
4.89
2150
4.88
18 Aug
0113
4.90
0506
4.91
18 Sep
0722
3.38
0809
3.38
21 Oct
0844
3.73
1011
3.73
12 Nov
1444
3.60
1532
3.60
11 Dec
0917
4.08
1147
4.09
15 3an 85
1434
4.43
1610
4.44
9 Feb
0906
4.06
1415
4.06
1651
4.08
2136
4.10
10 Feb
0107
4.11
0549
4.11
6 Mar
1436
4.22
1703
4.24
9 Apr
0834
4.61
0942
4.62
6 May
1512
4.98
1811
4.98
Water level elevation
(MSL)
4.50
4.30
4.30
4.29
4.28
4.28
4.28
5.82
5.82
5.47
5.47
5.62
5.61
5.13
5.13
4.78
4.78
5.15
5.15
4.95
5.12
5.12
5.11
4.99
4.97
4.59
4.57
4.24
4.23
4.52
4.31
4.32
4.31
4.32
4.30
4.29
5.82
5.82
5.47
5.47
5.60
5.60
5.12
5.11
4.77
4.76
5.14
5.14
5.12
5.10
5.09
5.09
4.98
4.96
4.59
4.58
4.22
4.22
6-265
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT KILL DEVIL HILLS
Depth to water
from
Weil
Measurement
Measurement
measuring
I.D.
Date
Time
(ft)
K2B3
10 3ul 84
1420
4.75
17 Aug
0733
4.81
1102
4.66
1508
4.71
2152
4.75
18 Aug
0111
4.68
0507
4.82
18 Sep
0721
3.35
0808
3.37
21 Oct
0845
3.51
1012
3.61
12 Nov
1445
3.57
1533
3.59
11 Dec
0918
3.96
1148
4.02
15 Dan 85
1434
4.28
1611
4.29
9 Feb
0907
3.89
1415
4.03
1652
4.13
2138
3.92
10 Feb
0109
3.93
0550
4.11
6 Mar
1437
4.27
1703
4.12
9 Apr
0635
4.51
0944
4.45
6 May
1513
4.94
1811
4.86
K2C1
10 3ul 84
1313
3.51
17 Aug
0734
3.76
1110
3.80
1519
3.80
2132
3.77
18 Aug
0102
3.82
0455
3.83
18 Sep
0729
2.14
0812
2.15
21 Oct
0853
3.30
1049
3.30
12 Nov
1450
3.07
1542
3.06
11 Dec
0906
3.37
1132
3.37
15 3an 85
1427
J.85
1606
3.85
9 Feb
0910
3.22
1418
3.23
1654
3.25
2139
3.27
10 Feb
0112
3.30
0555
3.29
6 Mar
1431
3.20
1653
3.21
9 Apr
0840
3.71
0946
3.71
6 May
1521
4.24
1814
4.25
Water level elevation
(MSL)
3.99
3.93
4.08
<*.03
3.99
4.06
3.92
5.39
5.37
5.23
5.13
5.17
5.15
4.78
4.72
4.46
4.45
4.85
4.71
4.61
4.82
4.81
4.63
4.47
4.62
4.23
4.29
3.80
3.88
5.82
5.57
5.53
5.53
5.56
5.51
5.50
7.19
7.18
6.03
6.03
6.26
6.27
5.96
5.96
5.48
5.48
6.11
6.10
6.08
6.06
6.03
6.04
6.13
6.12
5.62
5.62
5.09
5.08
6-266
-------
TABLE 3
(continued)
GROUND-WATER LEVEL hEASUREMENTS
AT KILL DEVIL HILLS
Depth to water
from
Well
Measurement
Measurement
measuring point
Water level elevation
l.D.
Date
Time
(ft)
(MSL)
K2C2
10 3ul 84
1310
3.92
5.46
17 Aug
0736
4.16
5.22
1113
4.16
5.22
1320
4.30
5.08
2134
4.17
5.21
18 Aug
0104
4.16
5.22
0456
4.19
5.19
18 Sep
0731
2.60
6.78
0814
2.60
6.78
21 Oct
0853
3.64
5.74
1050
3.64
5.74
12 Nov
1451
3.50
5.88
1543
3.50
5.88
11 Dec
0908
3.74
5.64
1132
3.75
5.63
13 Jan 83
1427
4.19
5.19
1607
4.20
5.18
9 Feb
0911
3.65
5.73
1419
3.65
5.73
1655
3.68
5.70
2141
3.65
5.7 i
10 Feb
0113
3.73
5.65
0556
3.70
5.68
6 Mar
1429
3.70
5.68
1655
3.69
5.69
9 Apr
0839
4.11
5.27
0947
4.11
5.27
6 May
1522
4.60
4.78
1814
4.62
4.76
K2C3
10 3ul 84
1307
4.60
4.71
17 Aug
0738
4.60
4.71
1116
4.56
4.75
1321
4.61
4.70
2136
4.59
4.72
18 Aug
0105
4.58
4.73
0458
4.62
4.69
18 Sep
0732
3.15
6.16
0815
3.14
6.17
21 Oct
0854
3.98
5.33
1050
4.01
5.30
12 Nov
1453
3.92
5.39
1543
3.92
5.39
11 Dec
0910
4.15
5.16
1133
4.17
5.14
15 3an 83
1428
4.53
4.76
1607
4.55
4.76
9 Feb
0912
4.06
5.25
1420
4.10
5.21
1656
4.12
5.19
2143
4.10
5.21
10 Feb
0115
4.11
5.20
0557
4.15
5.16
6 Mar
1429
4.16
5.15
1656
4.13
5.18
9 Apr
0838
4.52
4.79
0948
4.51
4.80
6 May
1523
4.97
4.34
1815
4.95
4.36
6-267
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT KILL DEVIL HILLS
Depth to water
from
Weil
Measurement
Measurement
measuring
I.D.
Date
Time
(ft)
K2C4
10 Oul 84
1303
6.04
17 Aug
0742
5.94
1118
5.91
1522
5.90
2139
5.88
18 Aug
0106
5.91
0500
5.94
18 Sep
0733
5.45
0816
5.45
20 Oct
0854
5.40
1051
5.44
12 Nov
1453
5.53
1544
5.52
11 Dec
0911
5.87
1134
5.86
15 3an 85
1428
5.82
1607
5.85
9 Feb
0913
5.89
1421
5.93
1657
5.98
2144
5.97
10 Feb
0117
6.00
0559
6.00
6 Mar
1429
6.08
1656
6.06
9 Apr
0837
5.95
0949
5.93
6 May
1524
6.26
1816
6.24
K2D1
10 Qui 84
1328
4.66
17 Aug
0756
5.03
1126
5.03
1532
5.04
2122
5.06
18 Aug
0054
5.05
0448
5.07
18 Sep
0740
3.59
0819
3.59
21 Oct
0904
4.85
1315
4.85
12 Nov
1500
5.18
1555
5.17
11 Dec
0857
5.10
1120
5.11
15 3an 85
1420
5.73
1601
5.72
9 Feb
0920
5.03
1424
5.00
1700
4.98
2148
4.99
10 Feb
0120
5.00
0603
4.98
6 Mar
1422
4.73
1648
4.75
9 Apr
0858
5.12
0951
6.14
6 May
1533
5.69
1819
5.70
Water level elevation
(MSL)
2.94
3.04
3.07
3.08
3.10
3.07
3.04
3.53
3.53
3.58
3.54
3.45
3.46
3.11
3.12
3.16
3.13
3.09
3.05
3.00
3.01
2.98
2.98
2.90
2.92
3.03
3.05
2.72
2.74
7.14
6.77
6.77
6.76
6.74
6.75
6.73
8.21
8.21
6.95
6.95
6.62
6.63
6.70
6.69
6.07
6.08
6.77
6.80
6.82
6.81
6.80
6.82
7.07
7.05
6.68
5.66
6.11
6.10
6-268
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT KILL DEVIL HILLS
Depth to water
from
Well
Measurement
Measurement
measuring
l.D.
Date
Time
(ft)
K2D2
10 Jul 84
1332
7.40
17 Aug
0759
7.61
1128
7.62
1533
7.65
2124
7.66
18 Aug
0056
7.64
0446
7.63
18 Sep
0739
6.29
0818
6.29
21 Oct
0904
7.21
1316
7.20
12 Nov
1458
7.25
1556
7.26
11 Dec
0858
7.44
1121
7.45
15 Jan 85
1421
7.76
1602
7.78
9 Feb
0921
7.32
1425
7.35
1701
7.36
2150
7.38
10 Feb
0122
7.42
0604
7.41
6 Mar
1423
7.37
1649
7.39
9 Apr
0858
7.62
0952
7.62
6 May
1534
8.05
1820
8.04
K2D3
10 3ul 84
1337
7.53
17 Aug
0803
7.73
1129
7.75
1535
7.77
2126
7.78
18 Aug
0057
7.77
0444
7.75
18 Sep
0742
6.45
0820
6.45
21 Oct
0905
7.32
1316
7.32
12 Nov
1503
7.35
1554
7.36
11 Dec
0859
7.56
1121
7.57
15 3an 85
1421
7.85
1602
7.88
9 Feb
0922
7.44
1426
7.46
1702
7.47
21S2
7.50
10 Feb
0124
7.54
0606
7.53
6 Mar
1420
7.50
1647
7.50
9 Apr
0856
7.71
0950
7.72
6 May
1535
8.12
1820
8.15
Water level elevation
iMSL)
4.61
4.40
4.39
4.36
4.35
4.37
4.38
5.72
5.72
4.80
4.81
4.76
4.75
4.57
4.56
4.25
4.23
4.69
4.66
4.65
4.63
4.59
4.60
4.64
I'M
4.39
3.96
3.97
4.51
4.31
4.29
4.27
4.26
4.27
4.29
5.59
5.59
4.72
4.72
4.69
4.68
4.48
4.47
4.19
4.16
4.60
4.58
4.57
4.54
4.50
4.51
4.54
4.54
4.33
4.32
3.92
3.89
6-269
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT KILL DEVIL HILLS
Depth to water
from
Well
Measurement
Measurement
measuring
l.D.
Date
Time
1ft)
K2E1
10 3ul 84
1354
3.56
17 Aug
0804
3.65
1129
3.68
1537
3.74
2111
3.72
18 Aug
0048
3.65
0436
3.60
18 Sep
0747
3.00
0824
3.00
21 Oct
0912
3.00
1412
3.04
12 Nov
1507
2.90
1606
2.92
11 Dec
0850
3.49
1110
3.49
15 Dan 85
1414
3.26
1558
3.33
9 Feb
0925
3.30
1429
3.31
1705
3.3i>
2155
3.42
10 Feb
0131
3.47
0611
3.43
6 Mar
1412
3.64
1642
3.68
9 Apr
0955
3.38
0846
3.36
6 May
1543
3.73
1824
3.73
K2E2
10 3ul 84
1356
3.22
17 Aug
0803
3.38
1130
3.39
1536
3.48
2113
J.47
18 Aug
0046
3.36
0437
3.28
18 Sep
0746
3.10
082 3
3.12
21 Oct
0913
2.71
1412
2.76
12 Nov
1508
2.87
1607
2.86
11 Dec
0850
3.43
1110
3.40
15 3an 85
1415
3.14
1558
3.27
9 Feb
0926
3.34
1430
3.31
1706
3.38
2157
3.50
10 Feb
0132
3.54
0612
3.55
6 Mar
1414
3.66
1643
3.75
9 Apr
0956
3.11
0846
3.07
6 May
1544
3.39
1824
3.90
Water level elevation
1MSL)
1.7 6
1.67
1.64
1.58
1.60
1.67
1.72
2.32
2.32
2.32
2.28
2.42
2.40
1.83
1.83
2.06
1.99
2.02
2.01
1.98
1.90
1.85
1.89
1.68
1.64
1.94
1.96
1.59
1.59
1.96
1.80
1.79
1.70
1.71
1.82
1.90
2.08
2.06
2.47
2.4 2
2.31
2.32
1.75
1.78
2.04
1.91
1.84
1.87
1.80
1.68
1.64
1.63
1.52
1.43
2.07
2.11
1.79
1.28
6-270
-------
TABLE 3
(continued)
GROUHO-WAfER LEVEL ttASUREMENTS
AT KILL
DEVIL HILLS
Depth to water
from
Well
Measurement
Measurement
measuring point
Water level elevation
1.0.
Date
Time
(ft)
(MSL)
K2E3
10 3ul 84
1359
3.30
c. 16
17 Aug
0802
3.47
1.99
1131
3.51
1.95
1535
3.56
1.90
2115
3.56
1.90
18 Aug
0042
3.48
1.98
0439
3.42
2.04
18 Sep
0745
3.33
2.13
0822
3.35
2.11
21 Oct
0913
2.85
2.61
1413
2.89
2.57
12 Nov
1508
3.02
2.44
1607
3.05
2.41
11 Dec
0851
3.60
1.86
1111
3.56
1.90
15 3an 85
1415
3.31
2.15
1558
3.43
2.03
9 Feb
0927
3.50
1.96
1430
3.48
1.98
1707
3.58
1.88
2158
3.69
1.77
10 Feb
0134
3.73
1.73
0613
3.73
1.73
6 Mar
1414
3.84
1.62
9 Apr
1644
0957
1:8
1:8
0847
3.18
2.28
6 May
1545
3.52
1.94
1825
3.51
1.95
KJA1 10 Jul 84 1720 10.70 2.88
17 Aug 0832 10.19 3.39
1200 10.21 3.37
1601 10.20 3.38
2225 10.20 3.38
18 Aug 0228 10.20 3.38
0713 10.20 3.38
17 Sep 1649 9.23 4.35
1817 9.23 4.35
19 Oct 1541 8.32 5.26
1659 8.31 5.27
12 Nov 1138 9.30 4.26
1300 9.27 4.31
10 Dec 1408 10.33 3.25
1501 10.32 3.26
15 Dan 85 1358 10.23 3.35
1622 10.23 3.35
9 Feb 0940 9.57 4.01
1443 9. JO 3.98
1723 9.62 3.96
2214 9.65 3.93
»0 Feb 0147 9.66 3.92
0630 9.52 4.06
6 Mar 1457 10.24 3.34
1716 10.24 3.34
10 Apr 0818 10.37 3.21
1108 10.38 3.20
6 May 1625 10.18 3.40
1839 10.20 3.38
6-271
-------
TABLE 3
(continued)
GROUND-WATER LEVEL fCASUREMENTS
AT KILL DEVIL HILLS
Depth to water
from
Weii
Measurement
Measurement
measuring
l.D.
Date
Time
(ft)
K3A2
10
Oul 84
1724
10.60
17
Aug
0834
10.12
1201
10.12
1602
10.11
2227
10.14
18
Aug
0226
10.12
0714
10.12
17
Sep
1647
9.12
1816
9.12
19
Oct
1542
8.25
1700
8.24
12
Nov
1133
9.19
1259
9.18
10
Dec
1409
10.24
1502
10.23
13
Jan 85
1447
10.14
1623
10.13
9
Feb
0941
9.48
1444
9.52
1724
9.54
2216
9.58
10
Feb
0149
9.59
0632
9.59
6
Mar
1456
10.15
1717
10.14
10
Apr
0818
10.29
1109
10.30
6
May
1626
10.11
1839
10.13
K3A2B
10
Oul 84
1729
9.98
17
Aug
0832
9.50
1201
9.47
1604
9.48
2228
9.50
18
Aug
0224
9.49
0715
9.51
17
Sep
1643
8.48
1815
8.49
19
Oct
1543
7.65
1701
7.63
12
Nov
1136
8.55
1258
8.55
10
Dec
1411
9.60
1503
9.60
15
Jan 85
1448
9.50
1624
9.51
9
Feb
0942
8.87
1444
8.91
1725
8.95
2218
8.96
10
Feb
0151
8.94
0633
9.28
6
Mar
1453
9.52
1719
9.49
10
Apr
0819
9.67
1109
9.67
6
May
1627
9.56
1840
9.56
Water level elevation
(MSL)
2.93
}.41
3.4 1
3.42
3.39
3.41
3.41
4.41
4.41
5.28
3.29
4.34
4.35
3.29
3.30
3.39
3.40
4.05
4.01
3.99
3.95
3.94
3.94
3.38
3.39
3.24
3.23
3.42
3.40
2.96
3.44
3.47
3.46
3.44
3.43
3.43
4.46
4.43
3.29
5.31
4.39
4.39
3.34
3.34
3.44
3.43
4.07
4.03
3.99
3.98
4.00
3.97
J.42
3.45
3.27
3.27
3.38
3.38
6-272
-------
TABLE 3
(continued)
GROUND-WATER LEVEL tCASUREMENTS
AT KILL DEVIL HILLS
Well
Measurement
Measurement
l.D.
Date
Time
K3A3B
10 3ul 84
1731
17 Aug
0835
1203
1605
22 JO
18 Aug
0225
0716
17 Sep
1645
1816
19 Oct
1544
1702
12 Nov
1137
1258
10 Dec
1410
1503
15 Dan 85
1449
1625
9 Feb
0943
1445
1726
2220
10 Feb
0153
0635
6 Mar
1455
1718
10 Apr
0819
1110
6 May
1627
1841
K3B1
11 Jul 84
1500
17 Aug
0842
1207
1612
2237
18 Aug
0217
0655
17 Sep
1658
1809
19 Oct
1557
1731
12 Nov
1143
1313
10 Dec
1415
1519
15 3an 85
1456
1629
9 Feb
0958
1450
1728
2225
10 Feb
0200
0645
6 Mar
1501
1724
10 Apr
0846
1125
6 May
1637
1845
Depth to water
from
measuring point
(ft)
Water level elevation
(MSU
10. H
9.75
9.65
9.69
9.69
9.66
9.71
8.70
8.75
7.90
7.87
8.62
8.67
9.85
9.87
9.67
9.69
9.08
9.25
9.33
9.14
9.17
9.28
9.78
1:8
9.86
10.00
9.92
3.85
3.98
3.99
3.99
4.00
4.01
4.01
2.42
2.44
3.48
3.48
3.24
3.25
3.46
3.46
3.87
3.87
3.27
3.26
3.28
3 30
3.33
3.33
3.32
3.32
3.83
3.83
4.30
4.30
3.03
1 »2
3.52
3.48
3.48
3.51
3.46
4.47
4.42
5.27
5.30
4.55
4.50
3.32
3.30
3.50
3.48
4.09
3.92
3.84
4.03
4.00
3.89
3.39
1:11
3.31
3.17
3.25
6.44
6.31
6.30
6.30
6.29
6.28
6.28
7.87
7.85
6.81
6.81
7.05
7.04
6.83
6.83
6.42
6.42
7.02
7.03
7.01
6.99
6.96
6.96
6.97
6.97
6.46
6.46
5.99
5.99
6-273
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT KILL DEVIL HILLS
Depth to water
from
Well
Measurement
Measurement
measuring
I.D.
Date
Time
(ft)
K3C1
10
3ul 84
1652
4.28
17
Aug
0847
4.53
1218
4.55
1553
4.55
2326
4.57
18
Aug
0213
4.57
0650
4.57
17
Sep
V/03
3.21
1806
3.21
19
Oct
1605
4.31
1733
4.31
12
Nov
1148
4.44
1318
4.43
10
Dec
1419
4.49
1529
4.49
15
3an 85
1459
4.90
1633
4.90
9
Feb
1002
4.29
1453
4.30
1731
4.31
2228
4.31
10
Feb
0204
4.33
0648
4.33
6
Mar
1506
4.15
1727
4.16
10
Apr
0855
4.54
1128
4.54
6
May
1644
5.11
1848
5.11
Water level elevation
(MSL)
9.69
9.44
9.42
9.42
9 AO
9 AO
9.40
10.76
10.76
9.66
9.66
9.53
9.54
9.48
9.48
9.07
9.07
9.68
9.67
9.66
9.66
9.64
9.64
9.82
9.81
9.43
9.43
8.86
8.86
K3D1 11 3ul 84 1511 5.18 10.56
17 Aug 0855 5.36 10.38
1258 5.38 10.36
1614 5.34 10.40
2321 5.41 10.33
18 Aug 0206 5.41 10.33
0642 5.41 10.33
17 Sep 1545 4.11 11.63
1749 4.12 11.62
19 Oct 1610 5.29 10.45
12 Nov 1153 5.49 10.25
1325 5.48 10.26
10 Dec 1424 5.61 10.13
1535 5.60 10.14
15 Jan 85 1505 6.07 9.67
9 Feb 1009 5.40 10.34
6 Mar 1521 >.22 10.52
1738 5.22 10.52
10 Apr 0905 5.63 10.11
6 May 1656 6.26 9.48
1853 6.23 9.51
6-274
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT KILL DEVIL HILLS
Well
Measurement
Measurement
l.D.
Date
Time
K3D2
n
*
H-
OD
1512
17
Aug
0902
1224
1610
2315
18
Aug
0202
0639
17
Sep
1600
1747
19
Oct
1614
1737
12
Nov
1159
1323
10
Dec
1427
1546
15
3an 85
1505
1635
9
Feb
1017
1459
1735
2239
10
Feb
0207
0653
6
Mar
1519
1736
10
Apr
0905
1132
6
May
1658
1852
K3D3B
10
3ul 84
1544
17
Aug
0905
1222
1611
2318
18
Aug
0203
0640
17
Sep
1604
1750
19
Oct
1616
1738
12
Nov
1200
1325
10
Dec
1428
1547
15
00
c
*
r>
1506
1637
9
Feb
1018
1458
1736
2236
10
Feb
0209
0654
6
Mar
1520
1741
10
Apr
0906
1130
6
May
1657
1854
Depth to water
from
measuring point
(ft)
Water level elevation
(MSL)
6.62
9.26
9.25
9.28
9.27
9.29
9.29
8.17
8.06
9.08
9.10
9.32
9.31
9.27
9.27
9.75
9.78
9.17
9.16
9.18
9.17
9.20
9.21
9.12
%:V,
9.56
10.02
10.04
6.87
7.04
7.05
7.07
7.07
7.08
7.09
5.84
5.85
6.83
6.84
7.05
7.03
7.00
7.00
7.42
7.44
6.83
6.84
6.83
6.84
6.89
6.86
6.79
6.80
7.21
7.22
7.69
7.68
10.71
8.07
8.08
8.05
8.06
8.04
8.04
9.16
9.27
8.25
8.23
8.01
8.02
8.06
8.06
7.58
7.55
8.16
8.17
8.15
8.16
8.13
8.12
8.21
7.77
7.31
7.29
7.81
7.64
7.63
7.61
7.61
7.60
7.59
8.84
8.83
7.85
7.84
7.63
7.65
7.68
7.68
7.26
7.24
7.85
7.84
7.85
7.84
7.79
7.82
7.89
7.88
7.47
7.46
6.99
7.00
6
-275
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT KILL DEVIL HILLS
Depth to water
from
Well
Measurement
Measurement
measuring
I.D.
Date
Time
(ft)
K3E1
11 3ul 84
1521
4.43
17 Aug
0912
4.59
1229
4.59
1604
4.61
2304
4.62
18 Aug
0155
4.62
0557
4.65
17 Sep
1615
3.42
1741
3.40
19 Oct
1628
4.57
1742
4.57
12 Nov
1209
4.92
1400
4.92
10 Dec
1433
4.82
1558
4.82
15 3an 85
1510
5.29
1640
5.30
9 Feb
1025
4.67
1504
4.66
1740
4.66
2244
4.68
10 Feb
0216
4.66
0704
4.66
6 Mar
1512
4.45
1731
4.45
10 Apr
0942
4.90
1139
4.91
6 May
1710
5.50
1900
5.50
K3F1
10 3ui 84
1610
6.76
17 Aug
0920
6.87
1223
6.89
1558
6.91
2255
6.89
18 Aug
0145
6.90
0550
6.90
17 Sep
1623
6.10
1758
6.10
19 Oct
1652
6.74
1751
6.74
12 Nov
1218
6.84
1339
6.85
10 Dec
1441
6.76
1608
6.76
15 3an 85
1520
7.05
1648
7.05
9 Feb
1035
6.47
1510
6.49
1748
6.49
2254
6.51
10 Feb
0225
6.51
0713
6.50
6 Nar
1532
6.53
1748
6.53
10 Apr
0957
6.88
1144
6.88
6 Hay
1717
7.52
1908
7.52
Water level elevation
(MSL)
8.61
8.43
8.43
8.43
8.42
8.42
8.39
9.62
9.64
8.47
8.47
8.12
8.12
8.22
8.22
7.75
7.74
8.37
8.38
8.38
8.36
8.38
8.38
8.59
8.59
8.14
8.13
7.54
7.54
6.19
6.08
6.0 6
6.04
6.06
6.05
6.05
6.85
6.85
6.21
6.21
6.11
6.10
6.19
6.19
5.90
5.90
6.48
6.46
6.46
6.44
6.44
6.45
6.42
6.42
6.07
6.07
5.43
5.43
6-276
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT KILL DEVIL HILLS
Well
Measurement
Measurement
I.D.
Date
Time
K3G1
10 3ul 84
1624
17 Aug
0919
1214
1550
2246
18 Aug
0138
0539
17 Sep
1630
1800
19 Oct
1644
1748
12 Nov
1222
1345
10 Dec
1445
1614
15 Dan 85
1523
1651
9 Feb
1038
1512
1752
2256
10 Feb
0228
0715
6 Mar
1537
1752
10 Apr
1004
1146
6 May
1724
1911
K3G2
10 Jul 84
1627
17 Aug
0920
1215
1551
2247
18 Aug
0140
0540
17 Sep
1632
1801
19 Oct
1644
1749
12 Nov
1222
1345
10 Dec
1447
1615
15 San 85
1523
1652
9 Feb
1039
1513
1753
2257
10 Feb
0229
0716
6 Mar
1538
1753
10 Apr
1005
1146
6 May
1725
1912
Depth to water
from
measuring point Water level elevation
l££l_ (MSL)
4.65
<(.63
4.66
4.68
4.66
4.64
4.65
4.37
4.37
4.41
4.41
4.41
4.40
4.52
4.51
4.53
4.55
4.43
4.43
4.44
4.46
4.48
4.47
4.57
4.
1.82
1.84
1.81
1.79
1.81
1.83
1.82
2.10
2.10
2.06
2.06
2.06
2.07
1.95
1.96
1.94
1.92
2.04
2.04
2.03
2.01
1.99
2.00
1.90
d? ;J9
4.71
4.78
4.77
4.36
4.41
4.45
4.47
4.45
4.42
4.40
4.06
4.07
4.06
4.29
4.02
4.12
1.76
1.69
1.70
2.16
2.11
2.07
2.05
2.07
2.10
2.12
2.46
2.45
2.46
4.06 2.46
4.06 2.46
4.05 2.47
2.23
2.23
2-28
4.28 2.24
2.50
2.40
MI
2.33
1
2.29
2.11
4.44 2.08
4.58 1.94
4.58 |.94
1.91
^-61 1.91
6
-277
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENT S
AT KILL DEVIL HILLS
Depth to water
from
Well
Measurement
Measurement
measuring point
Water ievel elevation
l.D.
Date
Time
(ft)
(MSL)
K3G3
10 3ul 84
1630
4.23
2.25
17 Aug
0923
4.29
2.19
1216
4.32
2.16
1553
4.35
2.13
2249
4.32
2.16
18 Aug
0142
4.30
2.18
05 42
4.28
2.20
17 Sep
1635
3.95
2.53
1802
3.95
2.53
19 Oct
1644
3.92
2.56
1749
3.90
2.58
12 Nov
1223
3.92
2.56
1346
3.89
2.59
10 Dec
1448
4.19
2.29
1616
4.19
2.29
1 5 3
-------
WATER-LEVEL DATA
FOR
ATLANTIC BEACH
6-279
-------
TABLE 1
ATLANTIC OCEAN TIDAL MEASUREMENTS
AT ATLANTIC BEACH
Depth to water
from
Measurement
Measurement
measuring point
Water level ei<
Date
Time
(ft)
(MSL)
14 Oul 84
1005
13.95
2.94
19 Aug
0707
17.73
-0.84
1121
15.13
1.76
1516
15.25
1.64
1925
16.99
-0.10
2320
15.77
1.12
20 Aug
0315
16.03
0.86
0733
17.66
-0.77
17 Sep
0900
16.00
0.89
1318
13.92
2.97
18 Oct
0846
17.10
-0.21
1157
14.48
2.41
11 Nov
0820
11.05
5.84
1142
12.95
3.94
1628
14.95
1.94
12 Dec
0748
14.46
2.43
1202
14.90
1.99
1505
17.70
-0.81
18 Jan 85
1535
14.10
2.79
1710
14.04
2.85
11 Feb
0850
16.62
0.27
1238
15.43
1.46
1635
18.27
-1.38
2045
0.2a
12 Feb
0030
2.6a
0720
19.44
-2.55
8 Mar
1251
16.13
0.76
11 Apr
0805
18.05
-1.16
0905
17.29
-0.40
12 Apr
0917
17.74
-0.85
1218
16.08
0.81
7 May
1306
16.92
-0.03
1638
18.73
-1.84
^Estimated from tidal tables (NOAA, 1985)
6-280
-------
TABLE 2
BOCUE SOUND TIDAL hEASUREMENTS
AT ATLANTIC BEACH
Staff gauge
Measurement Measurement reading Water level elevation
Date Time (ft) (MSL)
14 Jul 84 1^20 0.94 _o 92
19 Aug 0825 1.43 -0*43
1110 2.85 0.99
1501 3.66 T.80
1906 2.13
1328 4.52
1211 3.90
1539 1.74
1728 4.13
11 Feb 0920 1.98
1315 3.30
1702 1.29
2115 2.50
0.27
2310 2.68 o.82
20 Aug 0307 3.10 i >4
0726 1.57 .0*29
17 Sep 0922 5.29 3.43
2.66
18 Oct 0808 1.76 _o 10
1103 2.64 o.78
11 Nov 0842 4.74 ? 88
1149 3.34 Uk8
1640 1.74 _q I?
12 Dec 0757 3.74
2.04
-0.12
18 3an 85 1553 3.22 1>36
2.27
0.12
1.44
-0.57
0.64
12 Feb 0040 4.90 3.04
0628 0.57 -1.29
8 Mar 1259 2.90 1.04
1811 4.44 2.58
11 Apr 0835 0.89 .0.97
0930 1.59 _o.27
12 Apr 0930 0.68 -1.18
1230 2.26 o.40
7 May 1339 2.15 0.29
1651 0.60 _1.26
6-281
-------
TABLE 3
GROUND-WATER LEVEL ~CASUREMENTS
AT ATLANTIC BEACH
Depth to water
frum
Well
Measurement
Measurement
measuring
l.D.
Date
Time
(ft)
A1A1
14 3ul 84
0950
6.88
19 Aug
0652
7.95
1052
7.97
1443
7.96
1853
7.93
2253
8.01
20 Aug
0244
8.01
0658
8.04
17 Sep
0917
5.97
1512
5.97
18 Oct
0831
7.12
0935
7.13
11 Nov**
0916
7.45
1040
7.39
12 Dec
1234
7.86
1512
7.96
18 Dan 85
1542
7.69
1717
7.65
11 Feb
0906
7.56
1250
7.64
1643
7.68
2059
7.70
12 Feb
0017
7.59
0615
7.20
8 Mar
1317
7.82
1533
7.85
11 Apr
0819
7.71
0909
8.08
7 May
1317
7.77
1655
7.84
A1A3
14 3ul 84
0955
8.04
19 Aug
0653
9.48
1051
8.44
1442
7.90
1854
8.97
2255
8.79
20 Aug
0242
8.33
0659
9.37
17 Sep
0916
7.76
1512
7.06
18 Oct
0832
8.94
0935
8.75
11 Nov**
0915
7.07
1040
7.41
12 Dec
1235
8.21
1513
9.39
18 3an 85
1542
8.21
1717
7.85
11 Feb
0907
8.78
1251
7.99
1644
9.43
2059
8.55
12 Feb
0018
6.70
0616
9.04
8 Mar
1316
10.01
1533
10.05
11 Apr
0820
8.07
0910
8.39
7 May
1317
9.01
1656
9.01
Water level elevation
(MSL)
3.80
2.73
2.71
2.72
2.75
2.67
2.67
2.64
4.71
4.71
3.56
3.55
3.23
3.29
2.82
2.72
2.99
3.03
3.03
3.04
3.00
2.98
3.09
3.46
2.86
2.83
2.97
2.60
2.91
2.84
2.58
1.14
2.18
2.72
1.65
1.83
2.29
1.25
2.86
3.56
1.68
1.87
3.55
3.21
2.41
1.23
2.41
2.77
1.84
2.63
1.19
2.07
3.92
1.58
0.61
0.57
2.55
2.23
1.61
1.61
6-282
-------
TABLE i
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT ATLANTIC BEACH
Depth to water
from
Well
I.D.
Measurement
Date
Measurement
Time
measuring
(ft)
A1B1
14
Jul 84
0940
4.08
19
Aug
0647
4.94
1056
5.85
1445
4.86
1857
4.86
2247
4.89
20
Aug
0249
4.91
0705
4.88
17
Sep
0913
2.03
1445
2.07
18
Oct
0821
4.12
1007
4.12
11
Nov**
0907
4.81
1031
4.79
12
Dec
1227
5.07
1522
5.09
18
Dan 85
1545
5.44
1720
5.44
11
Feb
0912
4.43
1302
4.44
1647
4.45
2103
4.43
12
Feb
0025
4.43
0622
3.10
8
Mar
1312
4.84
1525
4.82
11
Apr
0822
5.00
0920
5.00
7
May
1323
5.64
1658
5.64
A1B3
14
3ul 84
0938
4.97
19
Aug
0648
6.26
1057
5.90
1446
5.56
1858
6.03
2248
6.02
20
Aug
0251
5.77
0706
6.24
17
Sep
0914
4.48
1445
3.94
18
Oct
0822
5.76
1007
5.67
11
Nov**
0907
5.18
1031
5.22
12
Dec
1229
5.76
1523
6.39
18
Dan 85
1545
6.11
1721
5.89
11
Feb
0913
6.01
1304
5.55
1648
6.14
2103
5.90
12
Feb
0026
5.03
0623
5.72
8
Mar
1313
6.57
1525
6.75
11
Apr
0823
6.62
0921
6.51
7
May
1323
6.38
1659
6.95
Water level elevation
(MSL)
4.67
3.81
3.90
3.89
3.89
.86
.84
.87
.72
.68
4.63
4.63
3.94
3.96
3.68
3.66
3.31
3.31
4.32
4.31
4.30
4.32
4.32
5.65
3.91
3.93
3.75
3.75
3.11
3.11
3.71
2.42
2.78
3.12
2.65
2.66
2.91
2.44
4.20
4.74
2.92
3.01
3.50
3.46
2.92
2.29
2.57
2.79
2.67
3.13
2.54
2.78
3.65
2.96
2.11
1.93
2.06
2.17
2.30
1.73
6-283
-------
TABLE 3
(continued)
GROUND-WATER LEVEL (CASUREMENTS
AT ATLANTIC BEACH
Depth to water
from
Well
Measurement
Measurement
measuring
I.D.
Date
Time
(ft)
A1C1
14 3ul 84
0930
6.78
19 Aug
0642
7.32
1101
7.33
1451
7.35
1901
7.35
2241
7.37
20 Aug
0256
7.41
0710
7.38
17 Sep
0909
5.06
1418
5.09
18 (set
0813
6.78
1037
6.78
11 Nov**
0900
7.49
1023
7.49
12 Dec
1222
7.67
1531
7.68
18 3an 85
1548
8.11
1723
8.11
11 Feb
0917
7.04
1313
7.03
1653
7.05
2105
7.06
12 Feb
0028
7.02
0627
6.94
8 Mar
1308
7.49
151f
7.49
11 Apr
0825
7.62
0923
7.62
7 May
1328
8.23
17 02
8.25
A1C3
14 Ail 84
0930
5.82
19 Aug
0643
7.67
1102
7.63
1452
7.56
1902
7.64
2242
7.67
20 Aug
0257
7.61
0711
7.68
17 Sep
0910
5.80
1417
5.69
18 Oct
0812
7.17
1038
7.17
11 Nov**
0901
7.46
1022
7.45
12 Dec
1223
7.81
1532
7.94
18 3an 85
1550
8.14
1724
8.09
11 Feb
0918
7.48
1314
7.36
1655
7.48
2106
7.49
12 Feb
0029
7.29
0627
6.99
8 Mar
1309
7.87
1517
7.94
11 Apr
0826
8.0 2
0924
8.01
7 May
1328
8.32
1703
8.46
Water level elevation
(MSU
4.35
3.81
3.80
3.78
3.78
3.76
3.72
3.75
6.07
6.04
4.35
4.35
3.64
3.64
3.46
3.45
3.02
3.02
4.09
4.10
4.08
4.07
4.11
4.19
3.64
3.64
3.51
3.51
2.90
2,88
5.16
3.31
3.35
3.42
3.34
3.31
3.38
3.30
5.18
5.29
3.81
3.81
3.52
3.53
3.17
3.04
2.84
2.89
3.50
3.62
3.50
3.49
3.69
3.99
3.11
3.04
2.96
2.97
2.66
2.52
6-284
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT ATLANTIC BEACH
Depth to water
from
Well
Measurement
Measurement
measuring
l.D.
Date
Time
(ft)
A1D1
14 3ul 84
0854
2.42
19 Aug
0828
1.95
1107
2.67
1456
2.33
1906
2.67
2305
2.72
20 Aug
0303
2.49
0720
2.89
17 Sep
0925
1.72
1326
1.29
18 Oct
0800
2.56
1105
2.45
11 Nov**
0848
1.99
1008
1.94
12 Dec
1216
2.52
1541
3.01
18 Dan 85
1554
2.74
1728
2.57
11 Feb
0925
2.8 2
1317
2.45
1659
2.89
2111
2.80
12 Feb
0032
2.17
0632
1.79
8 Mar
1302
3.23
1506
3.50
11 Apr
0830
3.28
0927
3.21
7 May
1334
3.04
1648
3.45
A1D2
14 Oul 84
0852
2.18
19 Aug
0829
2.66
1108
2.44
1457
2.12
1905
2.43
2306
2.40
20 Aug
0305
2.26
0721
2.62
17 Sep
0925
1.48
1327
1.06
18 Oct
0801
2.26
1106
2.18
11 Nov**
0848
1.69
1008
1.71
12 Dec
1217
2.31
1542
2.78
18 3an 85
1554
2.53
1729
2.35
11 Feb
0927
2.59
1317
2.24
1659
2.66
2111
2.57
12 Feb
0033
1.96
0633
8 Mar
1303
2.97
1507
3.23
1 • Apr
0830
3.04
0928
2.97
7 May
1335
2.71
1649
3.22
Water level elevation
(MSL)
2.56
3.03
2.31
2.65
2.31
2.26
2.49
2.09
3.26
3.69
2.42
2.53
2.99
3.04
2.46
1.97
2.24
2.41
2.16
2.53
2.09
2.18
2.81
3.19
1.75
1.48
1.70
1.77
1.94
1.53
2.64
2.16
2.38
2.70
2.39
2.42
2.56
2.20
3.34
3.76
2.56
2.64
3.13
3.11
2.51
2.04
2.29
2.47
2.23
2.58
2.13
2.25
2.86
a
1.85
1.59
1.78
1.85
2.11
1.60
6-285
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT ATLANTIC BEACH
Depth to water
from
Well
Measurement
Measurement
measuring
l.D.
Date
Time
(ft)
A1D3
14 Oul 84
0851
2.66
19 Aug
0829
3.01
1109
2.79
1458
2.50
1904
2.79
2307
2.79
20 Aug
0306
2.64
0722
2.98
17 Sep
0926
1.87
1327
1.45
18 Oct
0801
2.51
1106
2.43
11 Nov**
0849
2.10
1007
2.05
12 Dec
1218
2.60
1543
3.05
18 3an 85
1555
2.76
1729
2.60
11 Feb
0928
3.03
1318
2.72
1700
3.11
2112
3.02
12 Feb
0034
2.45
0634
1.92
8 Mar
1304
3.10
1507
3.27
11 Apr
0831
3.18
0929
3.13
7 May
1335
3.24
1649
3.56
A2A1
14 Oul 84
1021
6.70
19 Aug
0640
6.97
1142
7.00
1531
6.95
1934
6.93
2 348
7.02
20 Aug
0326
6.99
0751
7.03
17 Sep
0845
5.36
1134
5.40
18 Oct
0856
6.56
1522
6.54
11 Nov**
0952
6.70
1124
6.66
12 Dec
124 2
7.26
1606
7.25
18 Jan 85
1601
7.21
1736
7.17
11 Feb
0933
7.14
1326
7.13
1708
7.17
2120
7.22
12 Feb
0043
7.09
0647
6.80
8 Mar
1342
7.32
1607
7.43
11 Apr
0840
7.46
0934
7.47
7 May
1346
7.16
1706
7.24
Water level elevation
(MSL)
2.40
2.05
2.27
2.56
2.27
2.27
2.42
2.08
3.19
3.61
2.55
2.63
2.96
3.01
2.46
2.01
2.30
2.46
2.03
2.34
1.95
2.04
2.61
3.14
1.96
1.79
1.88
1.93
1.82
1.50
J.42
3.15
3.12
3.17
3.19
3.10
3.13
3.09
4.76
4.72
3.56
3.58
3.42
3.46
2.86
2.87
2.91
2.95
2.98
2.99
2.95
2.90
3.03
3.32
2.8 0
2.69
2.6 6
2.65
2.96
2.88
6-286
-------
TABLE 3
(continued)
GROUND-WATER LEVa MEASUREMENTS
AT ATLANTIC BEACH
Depth to water
from
Well
Measurement
Measurement
measuring
I.D.
Date
Time
(ft)
A2A3
14 3ul 84
10 22
7.02
19 Aug
0643
7.63
1143
7.82
1528
10.73
1936
10.98
2351
10.97
20 Aug
0325
10.94
0752
11.14
17 Sep
0848
6.13
1135
5.87
18 Oct
0857
6.99
1523
6.41
11 Nov**
0953
6.29
1125
6.57
12 Dec
1243
7.28
1606
7.51
18 3an 85
1603
7.03
1737
6.97
11 Feb
0934
7.48
1327
7.33
1709
7.66
2121
7.45
12 Feb
0045
6.42
0648
7.13
8 Mar
1341
7.86
1606
7.92
11 Apr
0841
7.83
0935
7.82
7 May
1347
7.44
1707
7.69
A2A4
14 Jul 84
102}
8.72
19 Aug
0642
7.35
1144
7.23
1529
6.97
1938
7.18
23 52
9.24
20 Aug
0328
7.18
0753
7.39
17 Sep
0847
8.55
1134
8.26
18 Oct
0857
8.16
1524
7.67
11 Nov**
0953
7.53
1126
7.75
12 Dec
1244
8.10
1607
8.43
18 3an 85
1602
9.78
1737
9.70
11 Feb
0935
8.61
1327
9.39
1710
8.71
2122
8.53
12 Feb
0046
7.69
0649
8.43
8 Mar
1340
9.91
1605
9.91
11 Apr
0842
10.33
0935
10.29
7 May
1347
8.75
1708
9.04
Water level elevation
(MSL)
3.06
2.4-5
2.26
-0.65
-0.90
-0.89
-0.86
-1.06
3.95
4.21
3.09
3.67
3.79
3.51
2.80
2.57
3.05
3.11
2.60
2.75
2.42
2.63
3.66
2.95
2.22
2.16
2.25
2.2 6
2.64
2.39
1.20
2.57
2.69
2.95
2.74
0.68
2.74
2.53
1.37
1.66
1.76
2.25
2.39
2.17
1.82
1.49
0.14
0.22
1.31
0.53
1.21
1.39
2.23
1.49
0.01
0.01
-0.41
-0.37
1.17
0.88
6-287
-------
TABLE 3
(continued)
GROUND-WATER LEVEL KtASUREMENTS
AT ATLANTIC BEACH
Depth to water
from
Well
I.D.
Measurement
Date
Measurement
measuring
(ft)
A2B1
14 3ul 84
1037
1.96
19 Aug
0650
2.48
1150
2.48
1536
2.48
1942
Z.i J
2337
.51
20 Aug
0333
2.51
0800
2.52
17 Sep
0839
0.22
1046
0.22
18 Oct
0907
2.18
1412
2.18
11 Nov**
0941
2.61
1108
2.59
12 Dec
1250
2.95
1620
2.96
18 3an 85
1606
3.31
1740
3.29
11 Feb
0939
2.41
1337
2.38
1715
2.40
2125
2.40
12 Feb
0052
2.40
0655
1.77
8 Mar
1333
2.93
1555
2.94
11 Apr
0848
3.01
0938
3.03
7 May
1354
3.40
1712
3.41
A2B3
14 3ul 84
1043
2.66
19 Aug
0653
3.05
1151
3.04
1537
3.01
1943
3.03
2339
3.07
20 Aug
0334
3.04
0801
3.10
17 Sep
0839
1.20
1050
1.20
18 Oct
0907
2.72
1413
2.64
11 Nov**
0943
2.95
1108
2.95
12 Dec
1251
3.41
1621
3.47
18 3an 85
1607
3.62
1741
3.59
11 Feb
0941
3.07
1338
3.00
1716
5.05
2126
3.04
12 Feb
0053
2.90
0656
2.53
8 Mar
1335
3.52
1554
3.55
11 Apr
0847
3.56
0939
3.57
7 May
1356
3.72
1712
3.77
Water level elevation
(MSL)
4.71
4. 19
19
19
4.18
4.16
4.16
4.15
6.4 5
6.45
4.49
4.49
4.06
4.08
3.72
3.71
3.36
3.38
4.26
4.29
4.27
4.27
4.27
4.90
3.74
3.73
3.66
3.64
3.27
3.26
3.94
3.55
3.56
3.59
3.57
3.53
3.56
3.50
5.40
5.40
3.88
3.96
3.65
3.65
3.19
J.13
2.98
3.01
3.53
3.60
1.55
3.56
3.70
4.07
3.08
3.05
3.04
3.03
2.88
2.83
6-
288
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT ATLANTIC BEACH
Depth to water
from
Well
Measurement
Measurement
measuring
l.D.
Date
Time
(ft)
A2B4
14 Oul 84
1040
6.6 2
19 Aug
0652
6.75
1152
6.76
1540
6.71
1945
6.76
2340
6.84
20 Aug
0335
6.81
0802
6.88
17 Sep
0838
4.86
1048
4.83
18 Oct
0908
4.28
1414
4.21
11 Nov**
0942
4.32
1109
4.32
12 Dec
1251
4.63
1621
4.73
18 3an 85
1607
5.67
1741
5.66
11 Feb
0943
5.01
1339
5.00
1718
3.08
2127
4.99
12 Feb
0054
4.81
0658
4.68
8 Mar
1334
5.80
1554
5.82
11 Apr
0847
6.04
0940
6.04
7 May
1355
5.12
1713
5.20
A2C1
14 Oul 84
1055
1.99
19 Aug
0702
2.43
1158
1.86
1544
2.19
1948
2.34
2328
2.41
20 Aug
0340
2.27
0741
2.44
17 Sep
0826
1.02
0953
1.05
18 Oct
0921
2.06
1207
1.98
11 Nov**
0934
1.51
1054
1.41
12 Dec
1258
1.83
1630
2.09
18 3an 85
1612
1.96
1743
1.87
11 Feb
0945
1.81
1348
1.56
1721
1.73
2132
1.75
12 Feb
0058
1.40
0703
0.22
8 Mar
1324
2.22
1542
2.35
11 Apr
0851
2.58
0943
2.58
7 May
1402
2.43
1715
2.65
Water level elevation
(MSL)
0.13
0.00
-0.01
0.04
-0.01
-0.09
-0.06
-0.13
1.89
1.92
2.47
2.54
2.43
2.43
2.12
2.02
1.08
1.09
1.74
1.75
3.67
1.76
1.94
2.07
0.95
0.93
0.71
0.71
1.63
1.55
2.46
2.02
2.59
2.26
2.11
2.04
2.18
2.01
3.43
3.40
2.39
2.47
2.94
3.04
2.62
2.36
2.49
2.58
2.64
2.89
2.72
2.70
3.05
4.23
2.23
2.10
1.87
1.87
2.02
1.80
6-289
-------
TABLE 3
(continued)
GROUND-WATER LEVEL fCASUREMENTS
AT ATLANTIC BEACH
Depth to water
from
Weil
Measurement
Measurement
measuring
l.D.
Date
Time
(ft)
A2C3
14 3ul 84
1057
2.24
19 Aug
0700
2.95
1159
2.42
1545
2.17
1947
2.72
2330
2.60
20 Aug
0342
2.42
0742
2.94
17 Sep
0825
1.84
0954
1.69
18 Oct
0921
2.60
1207
2.16
11 Nov**
0935
1.61
1054
1.58
12 Dec
1258
2.20
1631
2.93
18 Jan 85
1612
2.43
1744
2.23
11 Feb
0946
2.55
1348
2.13
1722
2.80
2133
2.46
12 Feb
0059
1.50
0704
1.84
8 Mar
1324
3.18
1542
3.51
11 Apr
0851
3.36
0944
3.21
7 May
1403
2.94
1716
3.49
A2C4
14 Oul 84
1059
3.78
19 Aug
0703
3.81
1200
3.73
1546
3.63
1949
3.77
2331
3.79
20 Aug
0343
3.74
0743
3.88
17 Sep
0824
2.70
0954
2.69
18 Oct
0922
2.26
1208
2.16
11 Nov**
0935
2.18
1054
2.15
12 Dec
1300
2.60
1631
2.70
18 Dan 85
1613
2.99
1745
2.95
11 Feb
0947
2.76
1349
2.74
1723
2.81
2134
2.84
12 Feb
0100
2.54
0705
1.90
8 Mar
1325
3.27
1543
3.36
11 Apr
0852
3.33
0945
3.30
7 May
1404
3.12
1716
3.25
Water level elevation
(HSL)
2.37
1.66
2.19
2.44
1.89
2.01
2.19
1.67
2.77
2.92
2.01
2.45
3.00
3.03
2.41
1.68
2.18
2.38
2.06
2.48
1.81
2.15
3.11
2.77
1.43
1.10
1.25
1.40
1.67
1.12
0.78
0.75
0.83
0.93
0.79
0.77
0.82
0.68
1.86
1.87
2.30
2.40
2.38
2.41
1.96
1.86
1.57
1.61
1.80
1.82
1.75
1.72
2.02
2.66
1.29
1.20
1.23
1.26
1.44
1.31
•~These measurements were made using an electric water-level indicator.
6-290
-------
WATER-LEVEL DATA
FOR
PINE KNOLL SHORES
6-291
-------
TABLE 1
GROUND-WATER LEVEL fCASUREMENTS
AT PINE KNOLL SHORES
Depth to water
from
Well Measurement Measurement measuring point Water level elevation
I.D. Date Time (ft) (MSL)
P1A1 14 Dul 84
19 Aug
20 Aug
18 Sep
17 Oct
11 Nov**
12 Dec
18 3an 85
11 Feb
12 Feb
8 Mar
12 Apr
7 May
P1A2 14 Oul 84
19 Aug
20 Aug
18 Sep
17 Oct
11 Nov**
12 Dec
18 Dan 85
11 Feb
12 Feb
8 Mar
12 Apr
7 May
1220
0725
1137
1455
1935
0005
0433
0903
1045
1236
1352
1509
1351
1535
0806
0948
1438
1622
1000
1402
1739
2142
0110
0746
m
0947
1125
1457
1725
1218
0726
1138
1456
1937
0007
0434
0904
1046
1237
1353
1510
1352
1536
0814
0950
1439
1623
1001
1402
1740
2144
0111
0747
1356
1624
0947
1125
1458
1726
11.57
10.99
11.03
10.99
10.96
11.04
11.03
11.08
9.92
9.92
10.14
10.11
10.29
10.27
11.56
11.50
11.25
11.21
11.20
11.15
11.17
11.22
11.00
10.55
11:8
11.67
11.77
11.16
11.21
11.62
11.04
11.09
11.04
11.01
11.17
11.08
11.14
9.98
9.96
10.18
10.15
10.33
10.32
11.60
11.54
11.30
11.26
11.28
11.17
11.21
11.24
10.99
10.58
11.29
11.34
11.82
11.82
11.22
11.28
3.68
4.26
4.22
<*.26
4.29
4.21
4.22
4.17
5.33
5.33
5.11
5.14
4.96
4.98
3.69
3.75
4.00
4.04
4.05
4.10
4.08
4.03
4.25
4.70
m
3.58
3.48
4.09
4.04
3.66
4.24
4.19
4.24
4.27
4.11
4.20
4.14
5.30
5.32
5.10
5.13
4.95
4.96
3.68
3.74
3.98
4.02
4.00
4.11
4.07
4.09
4.29
4.70
3.99
3.94
3.46
3.46
4.06
4.00
6-292
-------
TABLE 1
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT PINE KNOLL SHORES
Depth to water
fro*
Well
Measurement
Measurement
measuring
l.D.
Date
Time
(ft)
P1A3
14 Oul 84
1219
11.65
19 Aug
0727
11.10
1139
11.12
1457
11.04
1938
11.05
20 Aug
0009
11.17
0436
11.12
0905
11.20
18 Sep
1046
10.03
1237
9.96
17 Oct
1353
10.19
1510
10.17
11 Nov**
1352
10.33
1535
10.37
12 Dec
0811
11.59
0950
11.52
18 3an 85
1439
11.32
1623
11.23
11 Feb
1003
11.26
1403
11.20
1742
11.27
2146
11.23
12 Feb
0112
10.82
0749
10.53
8 Mar
1357
11.33
1623
11.41
12 Apr
0947
11.84
1125
11.86
7 May
1459
11.29
1727
11.36
P1B1
14 3ul 84
1207
8.48
19 Aug
0731
7.90
1142
7.91
1501
7.94
1941
7.94
20 Aug
0013
8.00
0440
7.96
0908
7.98
18 Sep
1051
5.69
1258
8.70
17 Oct
1400
7.28
1525
7.28
11 Nov**
1356
7.93
1544
7.93
12 Dec
0822
8.57
1002
8.58
18 3an 85
1442
8.97
1626
8.96
11 Feb
1006
7.78
1406
7.78
1745
7.78
2150
7.79
12 Feb
0115
7.79
0754
7.60
8 Mar
1402
8.28
1632
8.29
12 Apr
1002
8.58
1128
8.58
7 May
1504
9.11
1730
9.11
Water level elevation
(MSL)
3.67
4.22
4.2 0
4.28
4.27
4.15
4.20
4.12
5.29
5.36
5.13
5.15
4.99
4.95
3.73
3.80
4.00
4.09
4.06
4.12
4.05
4.09
4.50
4.79
3.99
3.91
3.48
3.46
4.03
3.96
4.69
5.27
5.26
5.23
5.23
5.17
5.21
5.19
7.48
4.47
5.89
5.89
5.24
5.24
4.60
4.59
4.20
4.21
5.39
5.39
5.39
5.38
5.38
5.57
4.89
4.88
4.59
4.59
4.06
4.06
6-293
-------
TABLE 1
(continued)
GROUND-WATER LEVEL (CASUREMENTS
AT PINE KNOLL SHORES
Depth to water
from
Weil
Measurement
Measurement
measuring
I.D.
Date
Time
1ft)
P1C1
14 3ul 84
1140
2.80
19 Aug
0737
2.16
1148
2.19
1505
2.21
1944
2.21
20 Aug
0016
2.21
0444
2.22
0910
2.23
16 Sep
1056
0.14
1305
0.22
17 Oct
1405
1.58
1529
1.58
11 Nov**
1409
2.06
1549
2.09
12 Dec
0829
2.85
1007
2.86
18 3an 85
1446
3.27
1628
3.27
11 Feb
1007
2.11
1409
2.10
1748
2.10
2151
2.11
12 Feb
0118
2.07
8 Mar
0756
1.40
\m
m
12 Apr
1010
2.84
1132
2.95
7 May
1508
4.15
1732
3.64
P1C2
14 3ul 84
1142
2.69
19 Aug
0738
2.05
1147
2.09
1506
2.10
1945
2.11
20 Aug
0017
2.10
0446
2.11
18 Sep
0911
2.13
1058
0.0
17 Oct
1305
0.01
1406
1.46
11 Nov**
1530
1.48
1410
1.96
12 Dec
1549
1.96
0830
2.74
18 Jan 85
1008
2.75
1447
3.17
11 Feb
1629
3.17
1008
2.01
1409
1.99
1749
2.00
12 Feb
2153
1.98
0119
1.97
8 Mar
0757
1.36
1406
2.41
12 Apr
1638
2.42
1010
2.86
7 May
1132
2.85
1508
3.53
1732
3.53
Water level elevation
(MSL)
4.74
5.38
5.35
5.33
5.33
5.33
5.32
5.31
7.40
7.32
5.96
5.96
5.48
5.45
4.69
4.68
4.27
4.27
5.43
5.44
5.44
5.43
5.47
6.14
1:8!
4.70
4.59
3.39
3.90
4.74
5.38
5.34
5.33
5.32
5.33
5.32
5.30
7.43
7.42
5.97
5.95
5.47
5.47
4.69
4.68
4.26
4.26
5.42
5.44
5.43
5.45
5.46
6.07
5.02
5.01
4.57
4.58
3.90
3.90
6-294
-------
TABLE 1
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT PINE KNOLL SHORES
Depth to water
from
Well
Measurement
Measurement
measuring
I.D.
Date
Time
1ft)
P1C3
14 3ul 84
1143
2.81
19 Aug
0739
2.17
1146
2.19
1507
2.22
1946
2.23
20 Aug
0019
2.22
0447
2.23
0912
2.24
18 Sep
1100
0.15
1305
0.15
17 Oct
1406
1.59
1530
1.60
11 Nov**
1410
2.14
1550
2.15
12 Dec
0831
2.87
1009
2.87
18 Oan 85
1447
3.31
1629
3.31
11 Feb
1009
2.13
1410
2.11
1751
2.10
2155
2.10
12 Feb
0120
2.09
0757
1.56
8 Mar
1407
2.54
1638
2.54
12 Apr
1010
2.93
1132
2.96
7 May
1509
3.65
1733
3.66
P1C4
14 3ul 84
1145
3.14
19 Aug
0740
2.60
1145
2.60
1508
2.61
1948
2.63
20 Aug
0020
2.6 2
0449
2.65
0913
2.66
18 Sep
1056
0.12
1306
0.12
17 Oct
1407
1.97
1531
1.98
11 Nov**
1411
2.59
1550
2.54
12 Dec
0832
3.11
1010
3.13
18 Oan 85
1448
3.55
1630
3.54
11 Feb
1009
2.58
1411
2.59
1752
2.59
2158
2.54
12 Feb
0121
2.53
0758
2.39
8 Mar
1408
2.90
1639
2.87
12 Apr
1010
3.07
1132
3.21
7 May
1509
3.84
1733
3.83
Water level elevation
(MSL)
4.74
5.38
5.36
5.33
5.32
5.33
5.32
5.31
7.40
7 AO
5.96
5.95
5.41
5.40
4.68
4.68
4.24
4.24
5.42
5.44
5.45
5.45
5.46
5.99
5.01
5.01
4.62
4.59
3.90
3.89
4.41
4.95
4.95
4.94
4.92
4.93
4.90
4.89
7.43
7.43
5.58
5.57
4.96
5.01
4.44
4.42
4.00
4.01
4.97
4.96
4.96
5.01
5.02
5.16
4.65
4.68
4.48
4.34
3.71
3.72
6-295
-------
TABLE 1
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT PINE KNOLL SHORES
Depth to water
from
Well
Measurement
Measurement
measuring
1.0.
Date
Time
(ft)
P1D1
14
Jul 84
1200
6.71
19
Aug
0745
1151
1511
1950
6.03
6.05
6.05
6.08
20
Aug
0024
6.20
0455
0917
6.09
6.12
18
Sep
1100
3.94
1315
3.95
17
Oct
1414
1552
5.58
5.59
11
Nov**
1417
1602
6.28
6.24
12
Dec
0838
1023
6.73
6.73
18
Dan 85
1450
1632
7.15
7.14
11
Feb
1012
1414
>754
2158
5.95
5.93
5.93
5.92
12
Feb
0123
0802
5.97
5.88
8
Mar
1412
1651
6.46
6.48
12
Apr
1016
6.78
1137
6.80
7
May
1514
7.40
1736
7.41
Water level elevation
(MSL)
4.24
<*.92
4.90
4.90
4.87
4.75
4.86
4.83
7.01
7.00
5.37
5.36
4.67
4.71
4.22
4.22
3.80
3.81
5.00
5.02
5.02
5.03
4.98
5.07
fc8
4.17
4.15
3.55
3.54
P1E1 14 Jul 84 1126 6.11 3.22
3.73
3.71
3.74
3.69
3.68
3.68
3.67
5.31
5.29
4.21
4.20
3.80
3.81
3.29
3.30
3.23
3.23
3.84
3.83
3.82
3.82
3.79
4.36
3.36
3.33
3.10
3.09
2.99
2.98
14 Oul 84
1126
6.11
19 Aug
0748
5.60
1153
5.62
1515
5.59
1952
5.64
20 Aug
0026
5.65
0457
5.65
0919
5.66
18 Sep
1106
4.02
1324
4.04
17 Oct
1418
5.12
1556
5.13
1 1 Nov**
1426
5.53
1606
5.52
12 Dec
0844
6.04
1029
6.03
18 Jan 85
1453
6.10
1634
6.10
11 Feb
1015
5.49
1415
5.50
1757
5.51
2159
5.51
12 Feb
0125
5.54
0806
4.97
8 Mar
1415
5.97
1656
6.00
12 Apr
1024
6.23
1139
6.24
7 May
1518
6.34
1738
6.35
6-296
-------
TABLE 1
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT PINE KNOLL SHORES
Depth to water
from
Well
Measurement
Measurement
measuring
l.D.
Date
Time
1ft)
P1E2
14 3ul 84
1128
6.18
19 Aug
0750
5.67
1154
5.70
1516
5.71
1954
5.70
20 Aug
0027
5.78
0459
5.71
0920
5.73
18 Sep
1106
4.10
1325
4.13
17 Oct
1418
5.18
1557
5.18
11 Nov**
1427
5.56
1606
5.55
12 Dec
0844
6.10
1029
6.10
18 3an 85
1454
6.17
1635
6.17
11 Feb
1017
5.57
1416
5.57
1758
5.57
2200
5.60
12 Feb
0126
5.57
0807
5.18
8 Mar
1416
6.03
1656
6.05
12 Apr
1024
6.33
1139
6.31
7 May
1519
6.39
1739
6.42
P1E3
14 Jul 84
1130
6.09
19 Aug
0751
5.58
1155
5.60
1517
5.61
1955
5.61
20 Aug
0029
5.64
0500
5.62
0921
5.64
18 Sep
1107
4.03
1325
4.04
17 Oct
1419
5.11
1557
5.10
11 Nov**
1427
5.48
1607
5.50
12 Dec
0845
6.02
1030
6.02
18 3an 85
1454
6.09
1635
6.08
11 Feb
1018
5.49
1416
5.48
1758
5.48
2201
5.46
12 Feb
0127
5.50
0808
5.13
8 Mar
1416
5.95
1655
5.98
12 Apr
1024
6.22
1139
6.23
7 May
1519
6.31
1740
6.33
Water level elevation
(MSL)
3.21
3.72
3.69
3.68
3.69
3.61
3.68
3.66
5.29
5.26
4.21
4. 21
3.83
3.84
3.29
3.29
3.22
3.22
3.82
3.82
3.82
3.79
3.82
4.21
3.36
3.34
3.06
3.08
3.00
2.97
3.20
3.71
3.69
3.68
3.68
3.65
3.67
3.65
5.26
5.25
4.18
4.19
3.81
3.79
3.27
3.27
3.10
3.21
3.80
3.81
3.81
3.83
3.79
4.16
3.34
3.31
3.07
3.06
2.98
2.96
6
-297
-------
TABLE 1
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT PINE KNOLL SHORES
Depth to water
from
Well
Measurement
Measurement
measuring
l.D.
Date
Time
(ft)
P2A1
14 Jul 84
1403
12.14
19 Aug
0801
12.08
1126
12.16
1546
11.96
1926
11.93
20 Aug
0101
12.04
0424
11.87
0927
12.14
18 Sep
1036
10.68
1 157
10.64
17 Oct
1427
10.68
1607
10.60
11 Nov**
1301
11.10
1434
11.27
12 Dec
0855
12.24
1043
12.10
18 3an 85
1502
11.41
1641
11.36
11 Feb
1027
11.96
1422
11.85
1808
11.82
2205
11.79
12 Feb
0132
11.37
0812
10.82
8 Mar
1427
11.90
1708
11.99
12 Apr
1037
12.47
1145
12.46
7 May
1538
11.70
1744
11.67
P2A2
14 3ul 84
1352
12.25
19 Aug
0803
12.18
1129
12.24
1547
12.05
1929
12.02
20 Aug
0103
12.12
0427
12.08
0929
12.23
16 Sep
1037
10.75
1158
10.69
17 Oct
1428
10.77
1608
10.70
11 Nov
1439
11.27
12 Dec
0856
12.32
1044
12.19
18 Jan 85
1503
11.53
1642
11.48
11 Feb
1028
12.04
1422
11.94
1809
11.92
2206
11.87
12 Feb
0133
11.41
0813
10.99
8 Mar
1429
12.01
1707
12.08
12 Apr
1037
12.53
7 May
1145
12.55
1539
11.73
1745
11.78
Water level elevation
(MSL)
2.66
2.7 2
2.64
2.84
2.87
2.76
2.93
2.66
4.12
4.16
4.12
4.20
3.70
3.53
2.56
2.70
3.39
3.44
2.84
2.95
2.98
3.01
3.43
3.98
2.90
2.81
2.33
2.34
3.10
3.13
2.67
2.74
2.68
2.87
2.90
2.80
2.84
2.69
4.17
4.23
4.15
4.22
3.65
2.60
2.73
3.39
3.44
2.88
2.98
3.00
3.05
3.51
3.93
2.91
2.84
2.39
2.37
3.19
3.14
6-298
-------
TABLE 1
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT PINE KNOLL SHORES
Depth to water
from
Well
Measurement
Measurement
measuring
l.D.
Date
Time
(ft)
P2A3
14 3ul 84
1400
12.48
19 Aug
0802
15.11
1128
12.45
1548
12.21
1928
12.23
20 Aug
0104
12.32
0425
12.28
0928
12.48
18 Sep
1037
11.00
1158
10.88
17 Oct
1428
10.93
1608
10.91
11 Nov**
1304
11.45
1435
11.51
12 Dec
0857
12.49
1045
12.34
18 Dan 85
1503
11.73
1642
11.63
11 Feb
1029
12.27
1424
12.17
1810
12.18
2207
12.07
12 Feb
0134
11.47
0814
11.14
8 Mar
1428
12.30
1708
12.29
12 Apr
1037
12.77
1145
12.77
7 May
1540
11.95
1746
12.01
P2B1
14 3ui 84
1304
8.00
19 Aug
0753
7.85
1123
7.86
1523
7.87
1922
7.89
20 Aug
0035
7.91
0355
7.90
0932
7.92
"18 Sep
1023
6.02
1150
6.03
17 Oct
1433
7.36
1616
7.36
11 Nov**
1309
7.72
1448
7.63
12 Dec
0902
8.00
1055
7.99
18 Jan 85
1506
8.16
1646
8.15
11 Feb
1030
7.07
1427
7.10
1812
7.09
2211
¦.11
12 Feb
0139
7.08
0818
6.87
8 Mar
1432
7.69
1717
7.70
12 Apr
1048
7.79
1148
7.82
7 May
1545
8.32
1748
8.33
Water level elevation
(MSL)
2.63
2.68
? 56
2.90
2.88
2.79
2.8 3
2.63
4.11
4.23
4.18
4.20
3.66
3.60
2.62
2.77
3.38
3.48
2.84
2.94
2.93
3.04
3.64
3.97
2.81
2.82
2.34
2.34
3.16
3.10
3.55
3.70
3.69
3.68
3.66
3.64
3.65
3.63
5.53
5.52
4.19
4.19
3.83
3.92
3.55
3.56
3.39
3.40
4.48
4.45
4.46
4.44
4.47
4.68
3.86
3.85
3.76
3.73
3.23
3.22
6-299
-------
TABLE 1
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT PINE KNOLL SHORES
Depth to water
from
Well
Measurer, »nt
Measurement
measuring
l.D.
. Date
Tine
(ft)
P2C1
14
3u._, 84
1316
7.34
19
Aug
0742
6.36
1117
6.4 2
1541
6.39
1918
6.42
20
Aug
0056
6.44
0406
6.44
09? 5
6.46
18
Sep
1004
4.57
1139
4.58
17
Oct
1438
5.78
11
Nov«*
1315
6.11
1456
6.09
12
Dec
0912
6.41
1103
6.41
18
3an 85
..
11
Feb
1035
5.22
8
Mar
1436
5.71
1722
5.68
12
Apr
1052
6.10
7
May
1552
6.78
1750
6.79
Water level elevation
IMSL)
2.04
3.02
2.96
2.99
2.96
2.94
2.94
2.92
4.81
4.80
3.60
3.27
3.29
2.97
2.97
4.16
3.67
3.70
3.28
2.60
2.59
P2C2
\4 Oul 84
19 Aug
20 Aug
18 Sep
17 Oct
11 Nov»*
12 Dec
18 3an 85
11 Feb
12 Fet
8 Mar
12 Apr
7 Hay
1317
0738
1112
1538
1915
0049
0400
0937
1017
1136
1438
1622
1322
1456
0908
1059
1510
1648
1037
1431
1816
2213
0142
0824
1442
1723
1052
1150
1553
1751
1:11
5.18
5.20
5.21
5.22
5.22
5.23
3.34
3.35
4.56
4.57
4.90
4.88
5.20
5.20
5.28
5.28
4.01
4.05
4.04
4.03
4.01
3.33
4.49
4.50
4.92
4.93
5.59
5.59
f:l§
3.25
3.23
3.22
3.21
3.21
3.20
5.09
5.08
3.87
3.86
3.53
3.55
3.23
3.23
3.15
3.15
4.42
4.38
4.39
4.40
4.42
5.10
3.94
3.93
3.51
3.50
2.84
2.84
6-300
-------
TABLE 1
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT PINE KNOLL SHORES
Depth to water
from
Well
Measurement
Measurement
measuring
l.D.
Date
Time
(ft)
P2C3
14 Oul 84
1312
5.34
19 Aug
0739
4.90
1113
4.93
1539
4.95
1916
4.98
20 Aug
0050
4.99
0402
4.98
0938
4.99
18 Sep
1018
3.08
1137
3.10
17 Oct
1439
4.33
1623
4.33
11 Nov**
1323
4.68
1457
4.63
12 Dec
0910
4.95
1100
4.95
18 3an 85
1510
5.04
1648
5.03
11 Feb
1039
3.97
1432
3.80
1817
3.77
2215
3.78
12 Feb
0143
3.74
0825
3.06
8 Mar
1443
4.27
1724
4.27
12 Apr
1052
4.67
1150
4.90
7 May
1553
5.34
1752
5.35
P2C4
14 Oul 84
1315
5.48
19 Aug
0740
5.28
1114
5.29
1540
5.28
1917
5.29
20 Aug
0051
5.32
0403
5.31
0939
5.30
18 Sep
1018
4.11
1137
4.12
17 Oct
1439
4.51
1623
4.51
11 Nov**
1324
5.04
1457
5.04
12 Dec
0908
5.23
1101
5.24
18 3an 85
1511
5.35
1649
5.35
11 Feb
1040
4.38
1432
4.38
1817
4.39
2217
4.41
12 Feb
0144
4.39
0825
4.35
8 Mar
1443
4.43
1723
4.43
12 Apr
1052
4.88
1150
4.69
7 May
1554
5.18
1753
5.19
Water level elevation
(MSL)
2.57
3.01
2.98
2.96
2.93
2.92
2.93
2.92
4.83
4.81
3.58
3.58
3.23
3.28
2.9 6
2.96
2.87
2.88
3.94
4.11
4.14
4.13
4.17
4.85
3.64
3.64
3.24
3.01
2.57
2.56
2.33
2.53
2.52
2.53
2.52
2.49
2.50
2.51
3.70
3.69
3.30
3.30
2.77
2.77
2.58
2.57
2.46
2.46
3.43
3.43
3.42
3.40
3.42
3.46
3.38
3.38
2.93
3.12
2.63
2.62
6-301
-------
FABLE 1
(continued)
GROUND-WArER LEVEL MEASUREMENT
AI PINE KNOLL SHORES
Well
r n
Measurement
Ddtc
Measurement
Time
i«U*
P201
14 3ui 84
1323
19 Aug
0734
1109
1534
1911
20 Aug
0045
0410
0941
18 Sep
0959
1133
17 Oct
1453
1630
11 Nov**
1326
1514
12 Dec
0917
1129
18 3an 85
1513
1651
11 Feb
1048
1435
1820
2219
12 Feb
0146
0826
8 Mar
1445
1737
12 Apr
1106
1155
7 May
1607
1755
P2E1
14 Jul 84
1337
19 Aug
0728
1103
1528
1905
20 Aug
0039
0414
0945
18 Sep
0953
1116
17 Oct
1458
1634
11 Nov**
1337
1519
12 Dec
0923
1135
18 3an 85
1517
1655
11 Feb
t051
1438
1825
2221
12 Feb
0150
0829
8 Mar
1451
1743
12 Apr
1113
1158
7 May
1612
1757
Depth to water
Team
measuring point
(ft)
Water ievel elevation
(HSL)
6.99
6.65
6.67
6.69
6.69
6.71
6.69
6.71
5 .29
5.10
6.36
6.34
6.5 4
6.52
6.66
6.66
6.69
6.69
5.92
5.93
5.93
5.94
5.94
5.66
6.46
6.46
6.62
6.62
6.87
6.86
5.71
5.40
5.45
5.38
5.38
5.46
5.41
5.48
4.08
4.08
4.75
4.74
4.37
4.38
4.67
4.62
4.72
4.71
4.84
4.82
4.85
4.86
4.74
4.31
4.70
4.73
4.73
4.73
4.34
4.39
1.98
2.32
2.30
2.28
2.28
2.26
2.28
2.26
3.68
3.67
2.61
2.63
2.43
2.45
2.31
2.31
2.28
2.28
3.05
3.04
3.04
3.03
3.03
3.31
2.51
2.51
2.35
2.35
2.10
2.09
1.45
1.76
1.71
1.78
1.78
1.70
1.75
1.68
3.08
3.08
2.41
2.42
2.79
2.78
2.49
2.54
2.44
2.45
2.32
2.34
2.31
2.30
2.42
2.85
2.46
2.43
2.43
2.43
2.82
2.77
6-
302
-------
TABLE 1
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT PINE KNOLL SHORES
Well
Measurement
Measurement
l.D.
Date
Time
P2E2
14 Jul 84
1334
19 Aug
0729
1104
1529
1906
20 Aug
0040
0416
0946
18 Sep
0953
1117
17 Oct
1458
1634
1) Nov**
1337
1520
12 Dec
0924
1136
18 Dan 85
1518
1655
11 Feb
1052
1438
1826
2222
12 Feb
0151
0830
8 Mar
1450
1742
12 Apr
1113
1158
7 Hay
1612
1758
P2E3
14 3ui 84
1336
19 Aug
0730
1106
1530
1907
20 Aug
0041
0417
0947
18 Sep
0954
1117
17 Oct
1459
1635
11 Nov**
1337
1519
12 Dec
0924
1137
18 3an 85
1518
1656
11 Feb
1053
1439
1827
2223
12 Feb
0152
0830
8 Mar
1451
1743
12 Apr
1113
1158
7 May
1613
1758
Depth to water
from
measuring point Water ievel elevation
(ft) (MSL)
5.62 1.45
3.3b 1.72
3.41 1.66
5.32 1.75
5.32 1.75
5.40 1.76
5.35 1.72
5.43 1.64
4.08 2.99
4.09 2.98
4.68 2.39
4.66 2.41
4.36 2.71
4.37 2.70
4.65 2.42
4.58 2.49
4.68 2.39
4.67 2.40
4.81 2.26
4.77 2.30
4.93 2.14
4.81 2.26
4.68 2.39
4.24 2.83
4.70 2.37
4.74 2.33
4.74 2.33
4.74 2.33
4.37 2.70
4.43 2.64
5.95 1.21
5.62 1.54
5.66 1.50
5.58 1.58
5.59 1.57
5.65 1.42
5.61 1.55
5.70 1.46
4.31 2.85
4.33 2.83
4.90 2.26
4.88 2.28
4.49 2.67
4.52 2.64
4.82 2.34
4.75 2.41
4.82 2.34
4.81 2.35
5.00 2.16
4.92 2.24
4.98 2.18
4.97 2.19
4.84 2.32
4.39 2.77
4.83 2.33
4.85 2.31
4.85 2.31
4.85 2.31
4.48 2.68
4.53 2.63
**These measurements were made using an electric water-level indicator.
6-303
-------
WATER-LEVEL DATA
FOR
SURF CITY
6-305
-------
TABLE 1
ATLANTIC OCEAN TIDAL MEASUREMENTS
AT SURF CITY
Depth to water
from
Measurement Measurement measuring point Water level elevation
Date Time (ft) (MSL)
21 Aug 84
0645
22.23
-0.23
1045
22.00
0.00
1527
20.34
1.66
1850
21.20
0.80
2253
22.55
-0.55
22 Aug
0326
20.30
1.70
0716
22.30
-0.30
10 Nov
1409
22.49
-0.49
1711
20.99
1.01
13 Dec
0729
20.59
1.41
21 3an 85
1420
21.29
0.71
12 Feb
1315
1.4d
1750
-0.7d
2225
-0.1^
13 Feb
0145
1.9
0702
-0.4d
1020
-1.0d
8 Mar
0814
17.29
4.71
1028
19.77
2.23
13 Apr
1118
-0.3a
8 May
0901
1.4a
Estimated from tidal tables (NOAA, 1985).
6-306
-------
TABLE 2
INTRACOASTAL WATERWAY WATER-LEVEL MEASUREMENTS
AT SURF CITY
Staff gauge
Measurement
Measurement
reading
Water level el<
Date
Time
(ft)
(MSL)
21 Aug 84
0708
1.62
1.12
1106
0.95
0.45
1518
1.38
0.88
1917
2.05
1.55
2245
1.54
1.04
22 Aug
0351
1.37
0.87
0709
1.68
1.18
18 Sep
1614
2.26
1.76
1845
2.28
1.78
16 Oct
0752
2.24
1.74
1130
2.30
1.80
10 Nov
1358
2.09
1.59
1726
1.47
0.97
13 Dec
0735
0.72
0.22
0852
0.72
0.22
21 Oan 85
1640
0.50
0.00
12 Feb
1310
1.99
1.49
1745
1.56
1.06
2*18
0.70
0.20
13 Feb
0138
0.91
0.41
0658
1.53
1.03
1015
0.83
0.35
8 Mar
0802
1.59
1.09
1034
2.20
1.70
13 Apr
1021
0.21
-0.29
1215
-0.01
-0.51
8 May
0805
1.10
0.60
0958
1.00
0.50
6-307
-------
TA8LE i
GROUND-WATER LEVEL MEASUREMENTS
AT SURF CITY
Weil
Measurement
Measurement
measuring
1.0.
Date
Time
(ft)
S1A1
21 Aug 84
0659
7.82
1054
8.02
1544
7.47
1858
7.41
2311
7.85
22 Aug
0335
7.66
0732
7.80
18 Sep
1554
6.72
1719
6.88
16 Oct
0738
6.46
1024
6.28
10 Nov
1438
7.10
1601
7.28
13 Dec
0712
8.01
0840
7.82
21 Jan 85
1022
7.78
1142
7.92
12 Feb
1300
6.65
1737
6.98
2202
7.53
13 Feb
0121
7.10
0640
7.11
0950
7.57
8 Mar
0833
7.10
0923
6.99
13 Apr
1108
8.32
1158
8.30
8 May
0847
7.79
0945
7.69
S1A2
21 Aug 84
0700
7.79
1055
8.03
1545
7.42
1859
7.38
2313
7.80
22 Aug
0336
7.61
0731
7.76
18 Sep
1554
6.75
1718
6.91
16 Oct
0739
6.50
1025
6.28
10 Nov
1439
7.00
1604
7.30
13 Dec
0713
7.96
0841
7.77
21 Dan 85
1024
7.72
1143
7.89
12 Feb
1301
6.75
1738
7.00
2203
7.55
13 Feb
0122
7.09
0641
7.13
0951
7.58
8 Mar
0832
7.07
13 Apr
0923
6.98
1108
8.34
1158
8.26
8 Hay
0848
7.76
0945
7.65
Depth to water
from
nt Water level elevation
(HSL)
1.51
1.31
1.86
1.92
1.48
1.67
1.53
2.61
2.4 5
2.87
3.05
2.23
2.05
1.32
1.51
1.55
1.41
2.68
2.35
1.80
2.23
2.22
1.76
2.23
2.3 4
1.01
1.03
1.54
1.64
1.29
1.05
1.66
1.70
1.28
1.47
1.32
2.33
2.17
2.58
2.80
2.08
1.78
1.12
1.31
1.36
1.19
2.33
2.08
1.53
1.99
1.95
1.50
2.01
2.10
0.74
0.82
1.32
1.43
6-308
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT SURF CITY
Depth to water
from
Well
Measurement
Measurement
measuring point
Water level elevation
l.D.
Date
Time
(ft)
(MSL)
S1A3
21 Aug 84
0702
8.41
1.03
1056
8.65
0.79
1546
7.82
1.62
1900
7.99
1.45
2308
8.49
0.95
22 Aug
0338
8.11
1.33
0730
8.35
1.09
18 Sep
1553
7.33
2.11
1717
7.55
1.89
16 Oct
0739
7.30
2.14
1025
6.89
2.55
10 Nov
1440
8.03
1.41
1607
8.10
1.34
13 Dec
0715
8.57
0.87
0842
8.23
1.21
21 3an 85
1025
8.22
1.22
1144
8.47
0.97
12 Feb
1302
7.63
1.81
1739
8.04
1.40
2204
8.42
1.02
13 Feb
0123
7.70
1.74
0642
8.11
1.33
0952
8.48
0.96
8 Mar
0831
7.61
1.83
0924
7.61
1.83
13 Apr
1108
9.02
0.42
1158
8.89
0.55
8 May
0849
8.35
1.09
0946
8.18
1.26
S1B1
21 Aug 84
0653
4.20
1.38
1058
4.21
1.37
1534
4.25
1.33
1908
4.15
1.43
2301
4.02
1.56
22 Aug
0342
4.13
1.45
0721
4.11
1.47
18 Sep
1546
3.54
2.04
1703
3.51
2.07
16 Oct
0732
2.69
2.89
0930
2.75
2.83
10 Nov
1427
3.42
2.16
1540
3.43
2.15
13 Dec
0703
3.96
1.62
0827
3.99
1.59
21 Dan 85
1017
4.13
1.45
1232
4.12
1.46
12 Feb
1254
3.43
2.15
1740
3.37
2.21
2206
3.40
2.18
13 Feb
0125
3.48
2.10
0648
3.45
2.13
0959
3.49
2.09
8 Mar
0826
3.91
1.67
0908
3.90
1.68
13 Apr
1118
4.38
1.20
1203
4.39
1.19
8 May
0855
3.84
1.74
0949
3.85
1.73
6-309
-------
TABLE 3
(continued)
GROUNDWATER LEVEL MEASUREMENTS
AT SURF CITY
Depth, to water
from
Well
Measurement
Measurement
measuring
I.D.
Date
Time
(ft)
S1B2
21 Aug 84
0654
4.11
1059
4.11
1535
4.14
1909
4.08
2303
4.03
22 Aug
0344
4.04
0722
4.01
18 Sep
1547
3.40
1703
3.38
16 Oct
0733
2.60
0930
2.65
10 Nov
1430
3.33
1545
3.33
13 Dec
0704
3.85
0828
3.86
21 Oan 85
1018
4.00
12)3
4.00
12 Feb
1255
3.30
1741
3.23
2207
3.28
13 Feb
0126
3.34
0649
3.31
0959
3.35
8 Mar
0826
3.72
13 Apr
0908
3.72
1118
4.50
1203
4.51
8 May
0856
3.70
0949
3.71
S1B3
21 Aug 84
0655
4.36
1100
4.40
1536
4.32
1911
4.25
2304
4.31
22 Aug
0345
4.27
0723
4.27
18 Sep
1547
3.64
1704
3.63
16 Oct
0733
3.06
0931
3.12
10 Nov
1431
3.72
1553
3.76
13 Dec
0705
4.28
0829
4.25
21 Oan 85
1018
4.29
1233
4.36
12 Feb
1255
3.66
1741
3.70
2208
3.90
13 Feb
0127
3.80
0649
3.81
1000
3.97
8 Mar
0827
4.07
0908
4.03
13 Apr
1118
4.72
1203
4.70
8 May
0857
4.15
0950
4.13
Water level elevation
(MSL)
1.26
1.26
1.23
1.29
1.34
1.33
1.36
1.97
1.99
2.77
2.72
2.04
2.04
1.52
1.51
1.37
1.37
2.07
2.14
2.09
2.03
2.06
2.0 2
1.65
1.65
0.87
0.86
1.67
1.66
0.90
0.86
0.94
1.01
0.95
0.99
0.99
1.62
1.63
2.20
2.14
1.54
1.50
0.98
1.01
0.97
0.90
1.60
1.56
1.36
1.46
1.45
1.29
1.19
1.23
0.54
0.56
1.11
1.13
6-310
-------
TABLE 3
(continued).
GROUND-WATER LEVEL MEASUREMENTS
AT SURF CITY
Depth to water
from
Well
Measurement
Measurement
measuring
l.D.
Date
Time
(ft)
S3A1
21 Aug 84
0641
10.68
1042
11.01
1458
10.31
1850
10.34
2254
10.77
22 Aug
0302
10.53
0639
10.58
18 Sep
1619
8.89
1817
9.14
16 Oct
0820
9.30
1459
8.68
10 Nov
1518
10.35
1655
10.33
1) Dec
0742
10.79
0856
10.54
21 Jan 85
1051
10.72
1427
11.08
12 Feb
1223
9.50
1722
9.87
2221
10.26
13 Feb
0140
9.73
0615
10.12
0928
10.43
8 Mar
0901
9.82
1014
10.02
13 Apr
1035
11.11
1135
11.05
8 May
0810
10.62
0923
10.46
S3A2
21 Aug 84
0642
10.46
1043
10.80
1501
10.07
1851
10.11
2255
10.99
22 Aug
0303
10.57
0641
10.36
18 Sep
1620
8.69
1819
8.94
16 Oct
0822
9.15
1500
8.51
10 Nov
1520
10.20
1656
10.15
13 Dec
0743
10.60
0857
10.35
21 Oan 85
1054
10.55
1427
10.93
12 Feb
1223
9.32
1723
9.70
2224
10.06
13 Feb
0141
9.56
0616
9.96
0929
10.28
8 Mar
0859
9.73
1014
9.82
13 Apr
1035
10.98
1135
10.91
8 May
0812
10.44
0924
10.28
Water level elevation
(MSL)
1.58
1.25
1.95
1.92
1.49
1.73
1.68
3.37
3.12
2.96
3.58
1.91
1.93
1.47
1.72
1.54
1.18
2.76
2.39
2.00
2.53
2.14
1.83
2 .44
2.24
1.15
1.21
1.64
1.80
1.58
1.24
1.97
1.93
1.05
1.47
1.68
3.35
3.10
2.89
3.53
1.84
1.89
1.44
1.69
1.49
1.11
2.72
2.34
1.98
2.48
2.08
1.76
2.31
2.22
1.06
1.13
1.60
1.76
6-311
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT SURF CITY
Depth to water
from
Well
I.D.
Measurement
Date
Measurement
Time
measuring
(ft)
S3A3
21 Aug 84
0643
10.82
1044
11.19
1459
10.26
1853
10.41
2256
10.56
22 Aug
0304
10.31
0642
10.69
18 Sep
1620
9.23
1818
9.57
16 Oct
0821
9.69
1500
8.98
10 Nov
1517
10.70
1654
10.59
13 Dec
0744
10.79
0857
10.58
21 3an 85
1055
10.76
1428
11.47
12 Feb
1224
9.84
1724
10.33
2226
10.69
13 Feb
0142
9.95
0616
10.51
0929
10.93
8 Mar
0902
9.99
1015
10.17
13 Apr
1035
11.45
1135
11.32
8 May
0811
10.86
0925
10.62
Water level elevation
(MSL)
1.10
0.73
1.66
1.51
1.36
1.61
1.23
2.69
2.35
2.23
2.94
1.22
1.33
1.13
1.34
1.16
0.15
2.08
1.59
1.23
1.97
1.41
0.99
1.93
1.75
0.47
0.60
1.06
1.30
S3B1 21 Aug 84 0715 8.32 1-63
1055 8.50
1444 8.31 1*^
1900 8.20 1-75
2247 8.26 I*69
22 Aug 0251 8.30 1-65
0653 8.25 1»70
18 Sep 1626 6.53 3.42
1751 6.55 3.40
16 Oct 0802 6.99 2.96
10 Nov 1455 7.78 2.17
1636 7.84 2.11
13 Dec 0755 8.31 1.64
0930 8.27 1.68
21 Dan 85
12 Feb 1229 7.29 2.66
8 Mar 0850 8.00 1.95
0951 7.98 1.97
13 Apr 1045 8.56 1-39
8 May 0821 8.22 1.73
0928 8.18 1.77
6-312
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT SURF CITY
Depth to water
from
Well
Measurement
Measurement
measuring point
Water level elevation
I.D.
Date
Time
(ft)
(MSL)
S3B2
21 Aug 84
0651
6.24
1.55
1050
6.40
1.39
1W9
6.23
1.56
1856
6.12
1.67
2240
6.22
1.57
22 Aug
0253
6.21
1.58
0648
6.17
1.62
18 Sep
1639
4.58
3.21
1753
4.61
3.18
16 Oct
0803
4.86
2.93
1357
4.62
3.17
10 Nov
1507
5.68
2.11
1629
5.72
2.07
13 Dec
0757
6.26
1.53
0905
6.20
1.59
21 Jan 85
1040
6.21
1.58
1507
6.38
1.41
12 Feb
1230
5.25
2.54
1726
5.35
2.44
2228
5.59
2.20
13 Feb
0144
5.45
2.34
0621
5.50
2.29
0936
5.65
2.14
8 Mar
0855
5.87
1.92
0953
5.83
1.96
13 Apr
1053
6.50
1.29
1141
6.50
1.29
8 May
0833
6.09
1.70
0929
6.07
1.72
S3B3
21 Aug 84
0652
6.55
1.27
1051
6.81
1.01
1445
6.49
1.33
1857
6.33
1.49
2241
6.58
1.24
22 Aug
0255
6.54
1.28
0649
6.47
1.35
18 Sep
1640
4.66
3.16
1753
4.72
3.10
16 Oct
0804
5.15
2.67
1358
4.71
3.11
10 Nov
1508
6.11
1.71
1631
6.18
1.64
13 Dec
0758
6.52
1.30
0906
6.41
1.41
21 Jan 85
1042
6.34
1.48
1507
6.74
1.08
12 Feb
1231
5.25
2.57
1727
5.90
1.92
2229
6.22
1.60
13 Feb
0145
5.98
1.84
0621
6.09
1.73
0936
6.35
1.47
8 Mar
0856
6.17
1.65
0953
6.14
1.68
13 Apr
1053
7.06
0.76
1141
7.03
0.79
8 May
0824
6.55
1.27
0930
6.49
1.33
6-313
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT SURF CITY
Well
Measurement
Measurement
measuring
I.D.
Date
Time
(ft)
S3B4
21 Aug 84
0'j54
6.96
1052
7.17
1447
6.54
1858
6.62
2243
7.02
22 Aug
0256
6.76
0650
6.84
18 Sep
1641
5.18
1754
5.30
16 Oct
0805
6.70
1359
6.02
10 Nov
1511
7.45
1633
7.38
13 Dec
0800
7.62
0907
7.39
21 Jan 85
1043
7.54
1508
8.21
12 Feb
1231
6.93
1728
7.40
2230
7.58
13 Feb
0146
7.00
0622
7.48
0937
7.79
8 Mar
0857
7.06
0953
7.15
13 Apr
1053
8.31
1141
8.19
8 May
0825
7.67
0931
7.51
S3B5
21 Aug 84
0655
6.77
1053
6.93
1448
6.77
1859
6.66
2244
6.76
22 Aug
0257
6.75
0651
6.71
18 Sep
1641
5.11
1754
5.14
16 Oct
0806
5.39
1359
5.16
10 Nov
1512
6.21
1634
6.25
13 Dec
0801
6.78
0908
6.72
21 3an 85
1039
6.71
1508
6.90
12 Feb
1232
5.75
1728
5.87
2231
6.07
13 Feb
0147
5.96
0622
6.01
0938
6.17
8 Mar
0854
6.18
0952
6.36
13 Apr
1053
7.01
1141
7.00
8 May
0832
6.60
0932
6.58
Depth to water
from
nt Water level elevation
(MSL)
1.19
0.98
1.61
1.33
1.13
1.39
1.31
2.97
2.84
1.45
2.13
0.70
0.77
0.53
0.76
0.61
-0.06
1.22
0.75
0.57
1.15
0.67
0.36
1.09
-1.00
-0.16
-0.04
0.48
0.64
1.55
1.39
1.55
1.66
1.56
1.57
1.61
3.21
3.18
2.93
3.16
2.11
2.07
1.54
1.60
1.61
1.42
2.57
2.45
2.25
2.36
2.31
2.15
2.14
1.96
1.31
1.32
1.72
1.74
6-314
-------
TABLE 3
(continued)
GROUND-WATER LEVEL MEASUREMENTS
AT SURF CITY
Depth to water
from
Weil
Measurement
Measurement
measuring
I.D.
Date
Time
1ft)
S3C1
21 Aug 84
0701
3.48
1100
3.10
1507
3.63
1904
3.46
2310
3.45
22 Aug
0311
3.51
0702
3.44
18 Sep
1610
2.67
1736
2.59
16 Oct
0748
2.61
1133
2.69
10 Nov
1448
3.00
1616
3.07
13 Dec
0819
3.44
0920
3.43
21 Jan 85
1030
3.41
1610
3.52
12 F eb
1245
2.72
1730
2.87
2213
2.98
13 Feb
0131
3.01
0631
2.98
0942
3.06
8 Mar
0841
3.31
0940
3.29
13 Apr
1100
3.73
1148
3.75
8 May
0838
3.29
0938
3.32
S3C2
21 Aug 84
0702
3.96
1101
4.08
1508
4.10
1906
3.94
2311
3.94
22 Aug
0314
3.99
0703
3.91
18 Sep
1610
3.12
1736
3.04
16 Oct
0749
3.16
1133
3.23
10 Nov
1449
3.55
1617
3.63
13 Dec
0820
3.99
0921
3.98
21 3an 85
1031
3.96
1610
4.05
12 Feb
1246
3.26
1731
3.39
2214
3.52
13 Feb
0133
3.57
0632
3.49
0942
3.58
8 Mar
0840
3.83
0939
3.80
13 Apr
1100
4.27
1148
4.29
8 May
0839
3.85
0938
3.87
Water level elevation
(MSL)
1.35
1.73
1.20
1.37
1.38
1.32
1.39
2.16
2.24
2.22
2.14
1.83
1.76
1.39
1.40
1.42
1.31
2.11
1.96
1.85
1.82
1.85
1.77
1.52
1.54
1.10
1.08
1.54
1.51
1.34
1.22
1.20
1.36
1.36
1.31
1.39
18
26
2
2
2.14
2.07
1.75
1.67
1.31
1.32
1.34
1.25
2.04
1.91
1.78
1.73
1.81
1.72
1.47
1.50
1.03
1.01
1.45
1.43
6-315
-------
TABLE 3
(continued)
GROUND-WATER LEVEL ICASUREMENTS
AT SURF CITY
Depth to water
from
Well Measurement Measurement measuring point Water level elevation
I.p. Date Time (ft) (MSL)
21 Aug 84
0703
4.80
0.79
1102
4.94
0.65
1509
4.89
0.70
1907
4.71
0.88
2312
4.76
0.83
22 Aug
0313
4.82
0.77
0705
4.75
0.84
18 Sep
1611
3.84
1.75
1736
3.78
1.81
16 Oct
0749
3.75
1.84
1134
3.79
1.80
10 Nov
1450
4.24
1.35
1618
4.30
1.29
13 Dec
0822
4.76
0.83
0921
4.73
0.86
21 3an 83
1032
4.69
0.90
1611
4.87
0.72
12 Feb
1247
4.08
1.51
1732
4.26
1.33
2215
4.49
1.10
13 Feb
0134
4.48
1.11
0632
4.39
1.20
0943
4.54
1.05
8 Mar
0839
4.70
0.89
0939
4.66
0.93
13 Apr
1100
5.21
0.38
1148
5.29
0.30
8 May
0840
4.77
0.82
0939
4.78
0.81
6-316
-------
APPENDIX F
6-317
-------
METHOD FOR COMPUTATION OF POROSITY
The effective porosity of the shallow aquifer in each study area
was computed by correlating precipitation with changes in water levels
observed in the observation well that was equipped with a continuous
stage recorder (Figures 1, 2 and 3). Well K3D1 in Kill Devil Hills, well
P2C1 in Pine Knoll Shores and well S3B1 in Surf City were equipped with
recorders for observing water-level changes.
6-318
-------
Figure 1. Relation between precipitation and ground-water levels at Kill Devil
Hills.
6-319
-------
Figure 2. Relation between precipitation and ground-water levels at Pine Knoll
Shores.
6-320
-------
Figure 3. Relation between precipitation and ground-water levels at Surf City.
6-321
-------
APPENDIX G
6-323
-------
METHOD FOR COMPUTATION OF PERCOLATION
Monthly percolation to the shallow aquifer was computed in general
conformance with procedures outlined by the EPA (Fenn, et al., 1975).
The computations were tabulated as shown below and the computation for
each parameter proceeded as follows:
Water Balance Computations
Month ~
Parameter J FMAMJJASOND Annual
(1) Etp
(2) P
(3) I
(4) I-Etp
(5) Z Neg (I-Etp)
(6) S
(7) AS
(8) Eta
(9) PERC
(1) Etp is potential evaportranspiration. Monthly estimates of
Etp were made using the Thornthwaite Method. The equation for
monthly Etp is:
£tp = 1.6 (cm)
where: a = (.675 x 10-6) e3 -(.771 x 10-4) £2 +V.01792E+.49239;
t = mean monthly temperature, in °C; and
1=12 . , 1.514
§W
is the temperature efficiency
index.
6-324
-------
The temperature efficiency index was computed with the aid of
Figure 1. Figure 2 was used to aid in computing Etp.
The monthly values of Etp were corrected for sunlight and days of
the month using Table 1.
The monthly Etp values were then converted from centimeters to
i nches.
P is mean monthly precipitation determined from National Weather
Service records or from local observations.
I is mean monthly infiltration. Mean monthly infiltration was
assumed to be equal to precipitation.
(I-Etp) was used to determine periods of moisture excess in the
soil. A negative value of (I-E^p) indicates the amount by which
the infiltration fails to supply the potential water need of the
vegetated area. A positive value indicates the amount of excess
water which is available for soil moisture recharge and
percolat ion.
z. Neg (I-Et,p) is the accumulated potential water loss. The accumu-
lated potential water loss with which to start the computations is
zero. This value is assigned to the last month having a positive
value of (I-Etp). This is reasonable because the soil moisture at
the end of the wet season is at field capacity.
S is soil moisture storage. This parameter represents the moisture
retained in the soil after a given amount of accumulated potential
water loss or gain has occurred.
The value of soil moisture storage when accumulated potential water
loss is zero was calculated by multiplying available water capacity
of the soil by thickness of the soil cover. The thickness of the
soil cover was estimated to be 0.5 feet based on the results of the
boring program. The available water capacity of the soil was
estimated to be 0.133 using Table 2 and the texture class of the
soils as estimated from field observations during the drilling
program.
AS is the monthly change in soil moisture and was computed using the
monthly soil moisture data determined in (6) above.
E^a is the actual monthly evapotranspiration. When (I-Etp) is posi-
tive, the rate of evapotranspiration is equivalent to Etp. When
U-Etp) is negative, evapotranspiration is limited to Eta = ^tp +
[(I-Etp)-AS].
6-325
-------
Equation of Curve"
i-(t/S),S" _
I
I
I
t
10
15
20
25
Monthly heaf index-(i)
Figure 1. Relation between monthly heat index and temperature
(Israelsen and Hansen, 1962)
0.2 J.3 15 a? » 2 3 4 s 7 » IS
Potential monthly evapolranspiroUon (e)-em
Figure 2.
Nanograph for computing monthly evapotranspiration
(Israelsen and Hansen, 1962)
6-326
-------
TABLE 1
RELATION OF CORRECTION FACTOR TO MONTH AND LATITUDE
(HAELSEN AND HANSEN, 1962)
N.
Lat.
J
F
M
A
M
J
J
A
S
0
N
D
0
1.04
0.94
1.04
1.01
1.04
1.01
1.04
1.04
1.01
1.04
1.01
1.04
10
1.00
0.91
1.03
1.03
1.08
1.06
1.08
1.07
1.02
1.02
0.98
0.99
20
0.95
0.90
1.03
1.05
1.13
1.11
1.14
1.11
1.02
1.00
0.93
0.94
30
0.90
0.87
1.03
1.08
1.18
1.17
1.20
1.14
1.03
0.98
0.89
0.88
35
0.87
0.85
1.03
1.09
1.21
1.21
1.23
1.16
1.03
0.97
0.86
0.85
40
0.84
0.83
1.03
lfll
1.24
1.25
1.27
1.18
1.04
0.96
0.83
0.81
45
0.80
0.81
1.02
1.13
1.28
1.29
1.31
1.21
1.04
0.94
0.79
0.75
50
0.74
0.78
1.02
1.15
1.33
1.36
1.37
1.25
1.06
0.92
0.76
0.70
6-327
-------
TABLE 2
RELATION BETWEEN SELECTED SOIL CHARACTERISTICS
(PERRIER AND GIBSON, 1980)
Texture class
USDA USCS
MIR
in./hr
Porosity
vol/vol
Ksat
in./hr
AWC
vol/vol
Evap
coef
1
CoS
GW
0.50
0.351
11.950
0.067
3.3
2
CoSL
GP
0.45
0.376
7.090
0.087
3.3
3
S
SW
0.40
0.389
6.620
0.133
3.3
4
FS
SM
0.39
0.371
5.400
0.122
3.3
5
LS
SM
0.38
0.330
2.780
0.101
3.4
6
LFS
SM
0.34
0.401
1.000
0.540
3.3
7
LVFS
SM
0.32
0.390
0.910
0.086
3.4
8
SL
SM
0.30
0.442
0.670
0.123
3.8
9
FSL
SM
0.25
0.458
0.550
0.131
4.5
10
VFSL
MH
0.25
0.511
0.330
0.117
5.0
11
L
ML
0.20
0.521
0.210
0.156
4.5
12
SIL
ML
0.17
0.535
0.110
0.199
5.0
13
SCL
SC
0.11
0.453
0.084
0.119
4.7
14
CL
CL
0.09
0.582
0.065
0.127
3.9
15
SICL
CL
0.07
0.588
0.041
0.149
4.2
16
SC
CH
0.06
0.572
0.065
0.078
3.6
17
SIC
CH
0.02
0.592
0.033
0.123
3.8
18
C
CH
0.01
0.680
0.022
0.115
3.5
Solid
waste
0.526
0.030
0.156
4.5
*USDA = USDA Soil Classification System, Co = coarse, C = clay, SI = silt,
S = sand, L = loam, F = fine, V = very;
USCS = Unified Soil Classification System, S = sand, M = silt, L = low
liquid limit, H = high liquid limit, W = well graded;
MIR = Minimum Infiltration Rate;
Ksat = Hydraulic Conductivity; and
AWC = Available Water Capacity.
6-328
-------
PERC is the monthly percolation rate. Monthly percolation was
determined as:
PERC = I-Eta - AS
Percolation computations for each of the study areas are summarized
in Tables 3, 4 and 5.
6-329
-------
TABLE 3
SUMMARY OF PERCOLATION COMPUTATIONS FOR KILL DEVIL HILLS
Parameter 1984 1985
May
June
July
Aug
Sept
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Etp
3.88
5.41
5.82
5.87
3.87
3.09
1.19
1.06
0.12
0.27
1.22
2.57
4.08
p
5.87
0.88
7.35
3.39
7.01
1.07
2.49
1.38
5.00
3.85
2.60
1.09
3.27
I
5.87
0.88
7.35
3.39
7.01
1.07
2.4S
1.38
5.00
3.85
2.60
1.09
3.27
I-Etp
1.99
-4.53
1.53
-2.48
3.14
-2.02
1.30
0.32
4.88
3.58
1.38
-1.48
-0.81
ENeg (I-Etp)
-4.53
-2.48
-2.02
-1.48
-2.29
S
0.80
0.00
0.80
0.00
0.80
0.00
0.80
0.80
0.80
0.80
0.80
0.00
0.00
AS
0.00
-0.80
0.80
-0.80
0.80
-0.80
0.80
0.00
0.00
0.00
0.00
-0.80
0.00
Eta
3.88
1.68
5.82
4.19
3.87
1.87
1.19
1.06
0.12
0.27
1.22
1.89
3.27
PERC
1.99
0.00
0.73
0.00
2.34
0.00
0.50
0.32
4.88
3.58
1.38
0.00
0.00
-------
TABLE 4
SUMMARY OF PERCOLATION COMPUTATIONS FOR ATLANTIC BEACH/PINE KNOLL SHORES
Parameter 1984 1985
May
June
July
Aug
Sept
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Etp
4.08
5.71
6.25
6.19
3.92
3.39
1.27
1.21
0.20
0.52
1.37
2.69
5.33
p
10.34
6.94
8.54
1.42
13.98
0.51
2.58
2.15
2.54
6.43
3.93
0.71
7.38
I
10.34
6.94
8.54
1.42
13.98
0.51
2.58
2.15
2.54
6.43
3.93
0.71
7.38
I-Etp
6.26
1.23
2.29
-4.77
10.06
-2.88
1.31
0.94
2.34
5.91
2.56
-1.98
2.05
ZNeg (I-Etp)
-4.77
-2.88
-1.98
S
0.80
0.80
0.80
0.00
0.80
0.00
0.80
0.80
0.80
0.80
0.80
0.00
0.80
AS
0.00
0.00
0.00
-0.80
0.80
-0.80
0.80
0.00
0.00
0.00
0.00
-0.80
0.80
Eta
4.08
5.71
6.25
2.22
3.92
1.31
1.27
1.21
0.20
0.52
1.37
1.51 ¦
5.33
PERC
6.26
1.23
2.29
0.00
9.26
0.00
0.51
0.94
2.34
5.91
2.56
0.00
1.25
-------
TABLE 5
SUMMARY OF PERCOLATION COMPUTATIONS FOR SURF CITY
Parameter 1984 1985
May
June
July
Aug
Sept
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Etp
4.16
5.79
6.02
5.81
3.76
3.16
1.19
1.43
0.28
0.71
1.84
3.07
5.37
P
6.45
0.89
9.01
4.79
18.94
0.49
1.16
1.32
2.01
5.08
1.66
0.71
2.76
I
6.45
0.89
9.01
4.79
18.94
0.49
1.16
1.32
2.01
5.08
1.66
0.71
2.76
I-Etp
2.29
-4.90
2.99
-1.02
15.18
-2.67
-0.03
-0.11
1.73
4.37
-0.18
-2.54
-2.61
ZNeg (I-Etp)
-4.90
-1.02
-2.67
-2.70
-2.81
-0.18
-2.72
-5.33
S
0.80
0.00
0.80
0.00
0.80
0.00
0.00
0.00
0.80
0.80
0.62
0.00
0.00
AS
0.00
-0.80
0.80
-0.80
0.80
-0.80
0.00
0.00
0.80
0.00
-0.18
-0.62
0.00
Eta
4.16
1.69
6.02
5.59
3.76
1.29
' 1.16
1.32
0.28
0.71
1.84
1.33
2.76
PERC
2.29
0.00
2.19
0.00
14.38
0.00
0.00
0.00
0.93
4.37
0.00
0.00
0.00
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