HomeMy WebLinkAboutJamesport Nuclear Power Station effects of Jetties on coastal erosionEffects of Jetties on Coastal Erosion
at Jamesport Nuclear Power Station
Prepared for
Town of Southold, New York
December, 1977
By
J. Douglas Glaeser*, Ph.D.
Consultant Geologist
36 Riverside Drive
New York, New York 10023
*Certified Professional
Geological Scientist No. 4124
'CONTENTS
Purpose and Scope of Report.
Summary of Results. . .
Recommendations.
Introduction. .
Coastal Processes - Long Island North Shore.
Previous Studies. .
Littoral Currents...
Predicting Results of Littoral Processes·
Analysis of Available Data.
Profiles. · ·
Results of Profile'Comparisons.'.
Implications of Bluff Retreat Rates. .
Sediment Sampling Uata. ~
Sieve Analysis .......
Results of Sieve Analysis.
Beach Samples. . %
Intertidal Samples.
Offshore Samples.
Inadequacy of Sediment'samPling--' --- ' Program.
Effects of Former Jetties at Jamesport Site.
Significance and Implications of Aerial
Photograph Comparisons. . .
Analysis of Borehole Data from Excavation Site
for Intake Structure and Channel.
Concluding Statements.
Resume of Report Author. .
Page
2
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TABLES
Table IA.
Horizontal Distance Measured Between Highest
Common Points on Profiles . .
Table IB.
Vertical Elevation Differences and Horizontal
Distances Between First Significant Nickpoint
on Landward (South) Side of Profiles
Table 2.
Aerial Photographs of 'Coastal Zone--Jamesport.
· 21
22
35
FIGURES '
Map of Jamesport Coastal Zone.
Page
10
Diagrammatic Explanation of Littoral Currents
Caused by Wave Refraction. · ·
12
3. Sand Budget for Jamesport Site-
March, 1974 to October, 1975. 17
4. Flow Diagram Explaining Bluff Retreat Process. 20
5. Sieve Analyses of Beach Sediments - Histograms. . . 27
6. Sieve Analyses of Intertidal Sediments - Histograms. 28
7. Sieve Analyses - Sediments from Water Depths of
6, 12 and 18 feet - Histograms. . 29
8. Copy of 1966 Aerial Photograph* Along Jamesport
Coastline. · · . . . . ]8
10.
11.
12.
13.
Copy of 1969 Aerial Photograph Along Jamesport
Coastline Showing Levon Property Jetties.
39
Copy of 1972 Aerial ~hotograph* Along Jamesport
Coastline..
40
Copy of 1974 Aerial Photograph* Along Jam,sport
Coastline. ·
41
Map of Long Island Lighting Company's Jamesport
Property Showing Coastline Width Differences to
East and West of Former Levon Property Jetties.
· 43
Map'of Borehole Sites Between Proposed Jetties
and Sediment Type Recovered from Borings. 45
* Original prints of 1966, 1972 and 1974 aerial photographs
are on file in office of Southold Town Supervisor. Copies
included in text lack scale accuracy and clarity of those
original prints. Copies are inclUded amohg the Figures
as illustrations only and originals should be used for any
definitive study of coastline and adjoining terrestrial
areas.
~ur~ose and Scope of Report
This report was prepared for the Town of Southold, New
York as part of its response to the proposed construction of
jetties which are to extend 800 feet from shoreline into
Long Island Sound at Long Island Light Company's property at
Jamesport. The two proposed rock jetties, located about
2.5 miles west of Mattituck Inlet, are to be built 924 feet
apart to form an intake channel having a bottom width of
700 feet. Dredging of this channel is to occur 12 feet
below mean low water at the channel mouth in Long Island
Sound and 27 feet below mean low water at the face of the
intake structures to be situated at the approximate position
of the present shoreline.
Three aspects of the proposed jetty construction will
clearly change the present balance of wave and littoral
current processes at and adjacent to the Jamesport site.
1. Presence of the jetties will disrupt the flow of
sediment carried by the littoral current resulting in
diminished nourishment and consequent erosion of ad-
jacent beaches and bluffs.
2. Dredging of material to form the intake channel and
the site of the intake structures is to be used for
both backfill and beach enrichment on the east side of
the jetties. The sand and gravel fraction of sediment
to be excavated and dumped to the east of the jetties
is of far smaller proportion to the total volume of
sediment to be excavated than shown in description of
work presented by LILCO in NANOP-E, Application Number
76-378. In addition, the requisite analyses of sand
and gravel grain size distributions do not accompany the
work proposal thus impeding determination of the
capability of this material to remain on the beaches
as replenishment sediment.
3. Because of the accumulation of sediment carried in
the littoral current both on one side of the jetties as
well as within the mouth of the intake channel, loss
of the natural replenishment sediment supplied by an
uninterrupted littoral current would result in increased
nearshore, beach and bluff erosion along the coastline
beyond the location of the jetties. In Application
Number 76-378, Long Island Lighting Company states
(Appendix A, Part I, Section 5) that as sand builds up
both adjacent to and between the jetties, this material
will be transferred to enrich the beach east of the
jetties.
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This report contains descriptions, analyses and inter-
pretations of the potential impacts of jetty construction
at the Jamesport site. The bulk of the data are publicly
available and were gathered by Long Island Lighting Company.
Much of this data come from the beach monitoring program
initiated by LILCO in March, 1974. An analysis and inter-
pretation of this beach monitoring program data were carried
out by the writer because LILCO had provided little informa-
tion concerning the meaning of the results in terms of coastal
zone erosion or adequacy of the excavated and dredged material
to effectively enrich the beaches to be primarily influenced
by jetty construction.
In addition, the present report describes changes in
the coastal zone between Duck Pond Point to the east and
Jacobs Point to the west of the Jamesport site as interpreted
from aerial photographs covering the time span from 1966
through 1974. Particular attention is given to the rapid
change in coast line characteristics which occurred with
construction of two 500-foot long jetties at this same site
which were constructed on the property then owned by Levon
and subsequently by Curtis-Wright Corporation. A listing of
all photographs studied is included with this report and
9"x9" aerial photographs for the years 1966, 1972 and 1974
accompany the report presented to the Town Supervisor, Town
of Southold. Xerox copies of those original photographs
accompany all other duplicates Qf this report.
Summary of Results of this Study and Recommendations
Presented to the Department of the Army, New York District,
Corps of Engineers.
summary of Results
I. Extensive coastal and bluffs erosion is presently taking
place along and adjacent to the Jamesport property.
A. Between March, 1974 and October, 1975, 1,105,567 cubic
yards of sediment have ~een lost from this coastal zone.
This fact is based on profile comparison studies made
by LILCO.
No comparative profile data are publicly available
subsequent to October, 1975, despite the written
commitment by LILCO to provide such data through
the present and continuing after construction of
the proposed jetties.
The ninety profile lines measured between March,
1974 and April, 1975, by LILCO are measured to
determine bluff retreat rates. An extreme value
~f 5 to 10 feet of recession are common for the
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comparison 'period. For the time spans used in
this comparison of profiles, sediment quantities be-
tween the former jetties have increased significantly
in contrast to the overall pattern of sediment loss
through the time period shown. This build-up of sedi-
ment between jetties is significant for these reasons:
1. This is at the location of the proposed intake
structures which is to be situated between the
two newly proposed jetties.
2. The present build-up here represents a loss of
sand from the littoral current, thus depleting
beaches further along the littoral flow directions.
The sediment accumulating can be
expected to be augmented if new jetties are con-
structed.
C. Comparisons of bluff retreat rates during March,
1974 -- April , 1975, exceed average retreat rates
elsewhere along the Suffolk County coastal zone and
bluffs. Thus,~annual retregt rates during the
period are 5 to 10 feet per year at the Jamesport
site.
D. More than half of the profile data to have been pro-
vided by LILCO have not been forthcoming. Profiles
made on the following dates are now on public file:
March, July, October,
April, October, 1975
April, 1976
December, 1974
Profile comparisons are available for the following
dates:
March, 1974-July, 1974
March, 1974-October, 1974
March-December, 1974
March, 1974-April, 1975
March, 1974-October, 1975
II.
1, The following profile data are not yet pub-
licly available assuming that the quarterly
dates of profile measurements established in
1974 are being followed through the present.
July, and December, 1975
July, October, December, 1976
March, July, October, 1977
2. In addition, as noted above, no comparisons
of profiles are available for public exam-
ination since the March, 1974-October, 1975
comparison in which a net sediment loss from
the profiled area totalled 1,105,567 cubic
yards.
Present retreat rates of the bluffs along and adjacent
to the LILCO Jamesport property indicate a finite time
period before which the Jamesport Nuclear Power Sta-
tion is threatened by direct attack by bluff slumping.
Such a threat to the power station would mandate ex-
traordinary coastal protection measures requiring
excessively high financial expenditures and result in
sealing off large amounts of sediment, the loss of
which to the littoral current system would further in-
crease coastal and bluff erosion and retreat well
beyond the area immediately adjacent to the Jamesport
site.
Previously constructed 550-foot jetties on the former
Levon Property have resulted in extensive shoreline ero-
sion east of those jetties because of entrapment of
sediment carried by the littoral current on the west
side of those former jetties. A number of publiclyavail-
able aerial photographs document decreases in beach'width
to 'the east and west of those 'for~er jetties.
The presently proposed jetties will extend 300 .feet
further from the seaward limit of the former jetties
at water depths of 12 feet below mean sea level. Such
jetties would therefore trap significantly larger quan-
tities of sediment carried in the littoral current
.~incr~asing e~osi0n adjacent t~the"proposed j~t~es.
Because the intake channel acts as a sediment sink,
there is a potential for an increase in fine sedi-
ment build-up here. These fines in addition to
those present in bore hole sites J-11, J-12 and
J-13 (described in the report) could contain a
relatively high percentage of clay minerals. Clay
minerals in a reducing environment are known sites
of precipitation of some radioactive materials
initially carried in solution in very low concen-
trations. Thus both surface and ground water
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movement through clay accumulations at and below
the intake channel as well as elsewhere offshore
from the diffuser system could result, in time,
in a build-up of radioactive materials in these
sed-iments. This subject is beyond the scope of
this report. It has not been considered in any
of the presently available environmental impact
statements on the Jamesport site.
III.LILCO's proposed beach nourishment programs, based on
periodic beach profiles and sieve analyses as well as
use of excavated sediment and sand bypass to enrich
beach zone to east of proposed jetties,are inadequate
to either predict the extent of, or to prevent in-
creases in, erosion of that zone.
It is not possible with the presently available beach
monitoring data initiated by LILCO to predict the
long-term extent of coastal erosion and bluff retreat.
B. The LILCO beach monitoring program along and adjacent
to its Jemesport property was to have included beach
profiles and sieve analyses taken at least twice
yearly since March, 1974.
Sieve analysis data are available for June, 1974
and October, I974 only. No later sieve analysis
data have been open for public examination. Also,
no written comparative analysis of the signifi-
cance of the 1974 sieve analysis data has been
presented. As part of this report, the signifi-
cance of this data is presented both in terms of the
enrichment program and in terms of its inadequacy
to statistically characterize the diverse nature
of the beach and nearshore sediments.
Three sets of data presented graphically in this
report represent the LILCO sieve data for June and
October 1974. One set of samples (Site 10+00) was
taken east of the former jetties. Site 40+00 lies
between the former jetties and ~ites 66+00 and 90+00
come from the area to the west.
2. In histograms of beach sample size analyses follow-
ing were observed:
a®
Larger percentages of coarse to very coarse
sand and granules were observed on both
sample dates on the beach between the posi-
tions of the former.jetties. Also, pebble
percentages are higher on either side of
these former jetties than elsewhere. Appar-
ently an energy shadow is created by these
former jetties.
Histograms of LILCO's sieved samples taken in June
and in October, 1974 from mean high water, mean sea
level and mean low water show:
a. Fine sediment is virtually absent in all samples
taken both in June and in October.
Medium sands are a minor component of all of
these intertidal zone samples in contrast to the
beach samples which contain a predominance of
medium grained sands.
Significant anomalies are observed in the October
samples which cannot be clarified without wave
characteristics prevailing during the sampling
period. The lack of such information makes it
possible to interpret the data both as favoring
and as negating the value of a sand by-pass sys-
tem. These data, without Supporting wave infor-
mation, are insufficient and ambiguous. They
are unsound for making a geologically intelligent
interpretation of their meaning.
4. Histograms from the four sample sites of sediment re-
covered at water depths of 6, 12 and 18 feet below
sea level indicate:
at
Between the site of the former jetties, sediment
size distributions become finer between 6 and
18 feet water depth in June.
The June samples east of the former jetties are
dominantly medium grained sand whereas to the
west of the jetties, coarser grain sizes prevail.
The offshore samples taken in October are gener-
ally dominated by medium grained sand on both
sides of the former jetties.
C. These points must be stressed concerning the inade-
quacies of the sieve data.
Data come from only four sample sites taken on
lines from the beach to water depths of 18 feet.
These four lines are perpendicular to the 11,000
foot long baseline along and adjacent to LILCO
Jamesport property. The June and October diverT
gence in the data indicate that four sample lines
cannot be used to characterize this coastal zone,
nor is a twice yearly sampling adequate to judge
the effectiveness of the proposed by-pass program.
Sediments between the former jetties have grain
distributions which differ from the other three
sets of samples implying jetty control on sediment
size at site 40+00.
No sampling has been made of various parts of the
beach to allow for comparisons of grain size from
mean high water toward the bluffs.
No sieve analysis data have been made available
since the October, 1974, sampling in contradiction
to the public statements by LILCO concerning an
ongoing sieve analysis program.
IV. Borehole data contracted for by LILCO at the proposed
excavation around the intake site show that more than
half of the material to be excavated and dumped to the
east of the proposed jetties is finer than sediment which
can remain on that beach. This fact significantly re-
duces the enrichment effects of the use of this excavated
material.
A. It can be assumed that the fine fraction of the
excavated sediment will have any 6r all of the follow-
ing negative consequences.
Increased turbidity of waters in the adjacent por-
tion of Long Island Sound during winnowing and
removal of the fine sediment by wave action.
2. Potential transport and sedimentation at Mattltuck
Inlet and other embayments.
Sedimentation of the removed fine sediment in deep
waters of Long Island Sound causing potential local
decreases in water depth or modifications in bottom
configurations.
Recommendations
Based on the information presently available and developed
this repor~ the following recommendations are made to the
United States Army, New York District, Corps of Engineers.
in
Jetty construction permits should not be granted until
all profile and sieve analysis data have been made
available and have been synthesized to show changes and
differences among portions of the coastal zone both east.
and west of the proposed jetty site.
Data from boreholes and from the sieve analyses indicate
that LILCO's proposed beach enri=hment plan is inadequate.
Other approaches to beach nourishment to prevent increased
coastal and bluffs erosion need to be assessed. This
implies that both the proposed spoils dumping and sand
by-pass programs require augmentation to prevent increased
erosion east of the proposed jetties.
Updated detailed surveys are essential to establish quan-
titative retreat rates of bluffs and coastal zone at and
adjacent to the Jamesport site.
On-going bluff retreat rates clearly call for long-term'
plans and commitments by both LILCO and the U.S. Army
Corps of Engineers to the projected consequences of po-
tential erosion and undermining of the Jamesport Nuclear
Power Station.
If such commitments are forthcoming, they must include
means of.replenishing beaches along the Southold shore-
line. This is crucial because the body of the information
presented in this report suggests the high probability
that bluff and shoreline erosion rates will increase along
the shoreline if these proposed jetties are permitted to
be constructed.
fe
The quantities of fine sediment shown in borehole data
and the probable amounts of fines which will accumulate
in the intake channel contain a sufficiently important
amount of clay that radionuclide build-up can be antici-
pated where chemically reducing condition prevail. Al-
though this report does not assess this potential envir-
onmental risk, the chemical and mlneralogic components
are present to permit precipitation of radioactive ma-
terials from Long Island Sound waters.
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INTRODUCTION
Coastal ProCessesU-Lon~ Island's North Shore
The coastal sector examined for this study lies between
the two relatively small points of land on either side of the
Jamesport site of Long Island Lighting Company's proposed
Nuclear Power Station. These two points are Duck Pond Point
on the east and Jacobs Point on the west. Figure 1 is a com-
posite map drawn from 7 1/2-minute quadrangle maps of this
study area. The two points are the closest locations to the
Jamesport site which would affect wave patterns approaching
the shoreline, refraction of those waves in the nearshore zone
and littoral drift directions resulting from wave refractions.
Contour lines of water depths below ~ean sea level out to the
18-foot depth contour very closely parallel the shoreline be-
tween Duck Pond and Jacobs Point indicating that these points
are the principal local controls on wave refraction.
Previous Studies
There is a lack of detailed studies of Long Island's
North Shore. The four principal reports concerning that
coastline are:
North Shore of Long Island, Suffolk County, New
York--Beach Erosion Control and Interim Hurricane
Study (Survey), 1969, by Department of the Army,
New York District, Corps of Engineers.
e
Erosion of the North Shore of Long Island, 1973,
by Davies, Axelrod and O'Connor, Marine Sciences
Research Center, SUNY Stony Brook, Technical Re-
port Series No. 18.
Long Island Sound Regional Study, Erosion and Se-
dimentation, and interim report, 1973, New England
River Basins Commission.
Effects of small groins on shoreline changes on
the North Shore of Suffolk County, New York, 1974,
by Olmholt, New York Ocean Science Laboratory,
Technical Report No. 0028.
Report %3 listed above calls the 81-mile long shoreline
of Suffolk County a zone of critical erosion along which
average coastline recession rates are 1 to 2 feet per year
and, at a few sites, 3.5 feet per year. That report lists
both natural and human causes for these erosion rates. The
natural~causes include winds, tides, storm-driven waves and
littoral currents. The human causes relate to building of
Pond
Point
Figure 1. Map of Jamesport Coastal Zone
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shoreline protection structures which inevitably deplete the
volume of sand in the littoral current system thus causing
increased erosion of unprotected portions of the coastline.
Shoreline protection structures which augment erosion else-
where along the shoreline include groins, jetties, seawalls,
revetments and bulkheads. That report also observes that
there is no predominant direction of littoral currents along
the shores of Long Island Sound.
Littoral Currents
Littoral currents are the result of both shoreline con-
figuration and the direction from which waves approach the
shoreline at any given time. The littoral current flows
parallel to the shore within the zone of breaking waves and
the current direction is governed by the refraction of waves
in the nearshore zone (Figure 2).
For example, on a straight stretch of coastline oriented
east-west, the littoral will flow westward when wind-driven
waves approach from the northeast or east. On the other hand,
the littoral current will flow eastward if wind-driven waves
approach the shoreline from the northwest or west.
Because wind velocities may be higher from one direction
than another, wave characteristics such as velocity, steep-
ness and length can vary in response to these wind velocity
differences. Such differences in wave characteristics have
direct influence, therefore, upon three aspects of the lit-
toral current in addition to its flow direction; velocity,
sediment volume and maximum grain sizes transported. Be-
cause of these variations in littoral currents, there is
usually a net flow of sediment in the littoral current di-
rection related to the prevailing winds over a given time
interval. It is because of these variables (and others) in
wind and wave characteristics that it is unreasonable to
attempt to predict specific littoral current directions as
well as volume and size of sediment transported along a given
stretch of any coastline based on generalizations or averages
for the entire coastal zone such as Long Island's North Shore.
Predicting Results of Littoral Processes
Types of measurements essential at any specific site,
such as are needed at Jamesport, to accurately predict the
results of littoral currents on sediment movement along the
shore include:
Weather and wave conditions--usUally measured at time
intervals throughout the 24-hour day. Such measure-
ments must span seasons to account for time variations
in weather and wave conditions.
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Di~ec~io-~'°'~-llttoml currents ~sulting from waves breaking at an
angle to the shore.
~.~. .~.~u-?. ~ ~o ,~ .~ ~.~ ~t~,~ .:-~ . -~.~..~z~
Net dir~tion "Backwa~ .... S~*' portion of
of ~h drift dir~tion ~h drift
Sediment movement along the beach occurs in the surf zone as littoral
drift and on the beach face as beach drift.
(From Anikouchine W. A., and Sternberg, R. W., 1973, fig. 10-4,
p. 162 and fig. 10-10, p. 168)
"Figure
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Wave condition~measurements include:
6ffshore wave heights
breaker heights
breaker types (spilling or plunging breakers)
wave period
wave approach angle
littoral current velocity
In addition, periodic changes in beach and nearshore
profiles are measured at closely spaced intervals. Ail of
this time-series data can be represented on maps and cross
sections which then can be compared to one another to show
daily, weekly, monthly or yearly rates and amounts of erosion
and deposition in the beach and nearshore zone as well as
changes in its adjacent bluffs or dunes. The actual time
spans between measurements is governed largely by the time
frame in which predictions of coastal changes must be made
and the degree to which prediction must match actual results
of the highly variable factors governing coastal processes.
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ANALYSIS OF AVAILABLE DATA
Because it was the purpose of this report to assess the
available information on coastline processes and changes at
the Jamesport site (past, present and potential future changes
should jetties be constructed), the kind of complete analysis
of coastline processes discussed earlier could not be carried
out. Such data for the Jamesport site, as described in the
previous section as crucial to predicting results of coastal
processes, simply have not been gathered. The Final Environ-
mental Statement related to construction of the Jamesport
Nuclear Power Station, written October, 1975, by the U.S.
Nuclear Regulatory Commission makes no assessment of coastal
processes and has no evaluation of the influences of the pro-
posed jetties on the coastal zone erosion processes presently
taking place at and adjacent to the site. Despite this ab-
sence of any consideration of coastal erosion which could
result from jetty construction, the New York District Engineer
of the Army Corps of Engineers stated in Public Notice No. 8816,
dated February 1, 1976, that "his preliminary environmental
review on presently available data has determined that the
EIS (environmental impact statement) prepared by the NRC
(Nuclear R~gulatory Commission) adequately addresses the
impacts associated with the proposed installation..."
In addition to this significant oversight by the District
Engineer in which he based his preliminary review on a doc-
ument which included no mention of the physical coastal pro-
cesses or the impacts of jetty construction on the adjacent
shoreline, there was also a failure to examine and, in Public
Notice 8816, assess any of the relevant data which were being
gathered by the applicant (LILCO) for the jetty construction
permit. LILCO had begun a beach monitoring program in March,
1974 which included a series of profiles taken perpendicular
to the shoreline at 90 or more sites along and adjacent to
its property of Jamesport. In addition to the profiles,
which were being taken four times annually, sediment samples
were gathered, apparently twice yearly, to determine grain
size characteristics of sediments comprising the beach and
nearshore zone.
The profiles were being measured to assess net changes
in the bluffs, beach and nearshore zone at and adjacent to
the site. The sediment sampling was being carried out to
assess the possible results of sand build-up at and between
the jetties and the effects of dredging the accumulated sand
for replenishing the beach to the east of the proposed jetty
site.
In addition to profiles and sediment sample analyses,
LILCO also had cores of sediment beneath the proposed site
of the intake channel. Part of the proposed construction plan
for this channel and the water intake structures for which it
and the jetties were to be built included dumping of the ex-
cavated sand and gravel on the beaches to the east as a start
-15-
to LILCO's proposed beach replenishment program.
Because the U.'S. Army Corps of Engineers had not assessed
this available data and because LILCO had not provided a
comprehensive public file of profile and sediment analysis
data with written summaries of what these data showed, the
Town of Southold undertook, through a contract with the author
of this report, to determine what data were available and what
did the data indicate in terms of present or potential erosion
at and adjacent to the Jamesport site as a result of proposed
jetty construction. Those data, their evaluations and inter-
pretations constitute the body of this report. The results
of the data synthesis and interpretations constituted the
basis upon which the recommendations were organized and pre-
sented to the. Corps of Engineers at the Public Hearing,
December ~977, in Riverhead, New York on behalf of the Town
of Southold.
Profiles
Starting in March, 1974, LILCO initiated a beach mon-
itoring program, one aspect of which was beach profiling.
This initial set of profiles extended perpendicular to the
shoreline along an 8,100 foot baseline. Along that baseline
about 90 profile lines were surveyed' through April,
1976. Each profile line is spaced at 100-foot intervals
perpendicular to the baseline and extends from the
toe of the bluffs, across the beach seaward to mean low
water. Beginning in April, 1975, the baseline was extended
from 8,100 feet to 11,000 feet and additional profile lines
were added to this extended baseline.
Profiles made on the following dates are now (December
8, 1977) on public file. ~ ~ccc-~
March, July, October, December 1974
April, October 1975
April 1976
Profile comparisons showing net changes in volume of
material within coastal sector surveyed are available for
the following dates:
March - July 1974
March - October 1974
March - December 1974
March 1974 - April 1975
March 1974 - October 1975
Assuming that the quarterly measurement schedules of
profilesha~e continued since December, 1974, the following
profile data have not yet been made publicly available (as
of December 8, 1977).
-16-
July, December 1975
July, October, December 1976
March (or April), July, October
1977
No profile comparisons are publicly available since the
March, 1974 - October, 1975 comparison.
A profile is simply a cross sectional view of the sur-
vey line showing the position and steepness of the slope of
each segment of the survey line from the bluff toe to mean
low water. By comparing two or more profiles taken along the
same line at different times of the year, changes in th~
position or any of the bluff crest or toe, the beach berm
beach crest or foreshore can be immediately determined. The
gain or loss at various positions along the survey line can
be algebraically summed to determine net gains and losses
during the time span between the two or more pr6file dates.
The algebraically summed area of gain and loss between any
two profiles along the same line can be added to the net
change in area for all profile lines during the time period
measured. This yields a value for net gain or loss in ~edi-
ment volume from the p~ofiled zone of any particular coastal
sector studied. Consistency of contours between each of the
ninety or more profile lines surveyed by LILCO is assumed in
making this calculation of net volume change between any two
dates for the entire zone of coastline being profiled. This
assumption is common practice in determining volume changes
and the parallelism of the offshore contours to the shore-
line (Figure 1) supports the assumption in the area profiled
by LILCO.
Results of Profile Comparisons
Figure 3 summarizes LILCO's data based on profiles
spanning March, 1974 through October, 1975. This sand
budget for the Jamesport site for the total time span of
available comparisons shows a net sediment loss of 1,105,567
cubic yards. The beach portion of the profiles shows a net
gain of 5,355 cubic yards of sediment whereas the offshore
portion of the profile shows a net loss of 1,110,922 cubic
yards.' This small gain of beach sediment in contract to
loss of offshore sediment requires a brief analysis of beach,
bluff and nearshore morphology in response to waves, wind,
running water and littoral currents.
Most profiles of beaches during nonstorm conditions
show a convex-upward form resulting from the net movement of
.sediment toward the shoreline. This sand and gravel is
derived from the nearshore zone and carried ashore by break-
ing waves. A part of the sediment carried ashore is from the
natural sediment supply moving parallel to the shoreline in
the littoral current. The convex upward beach profile de-
velops as nearshore bars attach to the beach and become part of
SAND BUDGET
Data based on LILCO comparisons of 90 profile lines m~asured March '74-October'-75
· Offshore Net Change
Time Span Beach I(below mean Iow water)
March '74 - July'74 +5853 cu.yds, no data +5853 cu,yds.
C 1170.6 DTL)'
March '74 - Oct. '74 +6393 cu.yds. - 609,I 18 cu.yds. - 602,725 cu.yd$.
f~120,545 DTL)
March '74 - Dec.'74 - 17,220cu.yds no. data -30,87.7 cu. yds.
· (21~5 DTL)
M~rch'74 -Oct. '75 +5355 cu.yds. - 1,110,922 cu.yd$. '-1,'~05,567 cu.vds.
(221,1'13.4 DTL')
No further comparisons ' 5 cubic yards of sand - I Dump Truck Load (DTL)
available after Oct.~75
Figure 3~ Sand Budget for Jamesport Site~
March, 1974 to October, 1975
-18-
the beach proper. Under nonstorm conditions the beach will
become broader as sediment from these shoreward migrating
bars produces on-going accretion to the beach face.
The reverse process occurs during storms when steep,
short period waves affect the nearshore zone. Under storm-
wave conditions, sediment is eroded from the beach face and
carried offshore to depths below the limits at which steep,
short periods can move the bottom sediment. Erosion of the
beach face during storm-wave conditions produces a flat or
concave-upward beach profile. Such a profile permits waves
to cross the beach and erode not only the backside of the
beach but also the bluffs or dunes as well. The sediment
removed from the back beach and bluffs or dunes area also
moves offshore beyond the influence of steep, short period
waves.
During this movement of sediment on and off shore during
nonstorm and storm conditions, sediment is also being trans-
ported laterally parallel to the shoreline in the littoral
current. Under natural conditions where an entire coastal
sector is not.stabilized by man-made structures, such as
groins or jetties, any sand lost from the immediate area as
it moves offshore during storms and carried laterally by the
littoral current is replenished by the sediment supply from
upcurrent in the littoral drift system. It is the presence
of jetties and groins, or any structures which prevent storm
waves from tapping the necessary sediment storage areas in
the backbeach, bluffs or dune areas, which ~ltimately depletes
the natural sediment supply from both the littoral current
system and the readvance of sand carried offshore during
storms back to the nearshore and beach environment to re-
develop the natural convex-upward profile of the non-storm
beach conditions. Time periods required for. any post-storm
recovery of a beach to its normal convex-upward profile may
range from several days to perhaps many weeks. It is in
this condition of a convex-upward profile, that waves, even
during spring high tides, cannot extend shoreward far enough
to erode the back-beach area or the bluffs or dunes.
Because there is an overall deficit in the sand budget
of the Suffolk County portion of Long Island's North Shore,
part of the total sediment budget which would aid in naturally
replenishing the beaches after storms have subsided is lost
from both the littoral current system and from the offshore-
onshore transfer of sediment which occurs during nonstorm
periods. In order to restore this sediment deficit the
natural process is to increase backbeach erosion and under-
cutting of the bluffs. Oversteepened bldffs slump in response
to undercutting causing a broad fan-shaped pile of sediment to
form at the toe of the bluffs. This newly slumped material
is then accessible to waves during spring high tides and
storms. Bluff slumping is also aided by water~runnin~ 'down
the bluff slope from surface runoff and leakage from ground
-19-
water stored in the bluff sediment itself. Freezing and
thawing of surface and ground water also are contributing
factors in the slumping process.
Figure ~ is a simple step by step diagram illustrating
the results of bluffs undercutting by wave action. As sug-
gested by the arrows in Figure 3, the process is cyclic and
repetitious resulting in an on-going bluff retreat toward
the south. It is important to stress that gains and losses
in the beach itself will be negligible if annual wind, wave
and storm conditions do not change radically whereas loss of
bluffs and of sediment from the offshore zone can be sub-
stantial. This significant loss of offshore material of
1,110,922 cubic yards measured by LILCO (Figure 3) with a
net gain of 5,355 cubic yards of sediment in the beach through
the time span of the profile data (March, 1974--October, 1975)
demonstrates this point. It is now essential to examine the
profile data for the bluffs to substantiate the inferences
made above and those suggested in Figure 4.
The 90 profile comparisons made by LILCO can be assessed
for periods in which comparative data have been made avail-
able (listed previously). Comparison data for the period
March, 1974, through April, 1975 are compiled in Table lA and
1~. The Table lists the site of each profile line, the gain
or loss of sediment at the bluff toe and the distance of
southward retreat of the lower part of the bluffs themselves.
The reader should be aware that as the angle'of bluff slope
decreases, the greater will be the retreat of the upper part
of the bluff crest. This decreases in slope angle is pri-
marily caused by slumping. The slumped portion appears as
an increment to the toe of the bluffs. The last column of
data listed in Table I shows the difference in gain or loss
of material at the toe of the bluff. The positive figures
listed in this last column of Table I, therefore, represent
the bulk of material available for redistribution by waves
affecting the backbeach area during spring high tides and
storms. Wind and running water also aid in redistributing
this sediment slumped to the toe of the bluffs across the
beach and nearshore environments. Regardless of the process
of redistribution, the beach maintains a reasonably consis-
tent width for specific gradients in the beach profile. The
beach can be thought of as a tank tread in which the beach
is the underside portion of the tread which gives the illusion
of not moving and the zones of measurable movement lie at its
margins, in this case, in the bluffs and offshore zones.
In terms of horizontal distance measured between the two
common highest points on the March, 1974 and April, 1975,
(Table IA)profiles an extreme value of bluff retreat is 22
feet. Many retreat values lie between 7 and 12 feet for the
13-month comparison period.
The second portion of TableIB shows both the vertical
change in position of the nickpoint Undercut line of waves)
Figure 4. Flow Diagram Explaining Bluff
Retreat Process
-21-
TABLE IA
Horizontal Distance Measured Between Highest Common Points on Profi
Site Distance (ft) * Site
Distance (ft)*
10+00 - 7.8 48 - 9.4
11 - 7.8 49 -18.7
12 - 7.8 50 -18.7
13 0 51 + 3.1
13+74 0 52 N.C.
14 + 4.7 53 -22.0
15 - .78 54 - 7.8
16 - 1.6 55 - 7.8
17 - 7.8 56+00 - 5.5
· 18 -10.1 57 0
19 - 9.4 58 - 6.2
20 - 7.8 59 - 9.4
20+32 -11.0 60 + 9.4
21 + 3.1 61 - 1.6
22 - 3.1 62 - 2.3
23 - 9.4 63 + 9.4
24 - 3.1 63+84 0
25 - 1.6 65 - 6.2
26 -11.0 66 + 3.1
27 - 7.0 67 - 7.8
28 - 3.1 68 -12.5
29 - 7.8 69 - 4.0
30 - 4.7 70 - 1.6
31 0 71 - 1.6
32 - 6.2 72 - 3.1
33 - 6.2 73 - 1.6
34 - 9.4 74 + 6.2
35 - 9.4 75 - 4.7
36+00 - 3.1 76 + 4.0
37 - 3.1 77 0
37+10 + 9~4 78 - 3.1
+19 N.C.** 79 + 1.6
+20 - 8.6 80 + 1.6
+70 N.C. 81 -4.7
38 N.C. 82 - .78
39 N.C. 83 - 1.6
40 N.C. 84+00 - 4.7
41 N.C. 85 - 3.1
41+31 N.C. 86 + 1.6
+50 - 3.1 87 + 1.6
42 - 9.4 88 - 3.1
+25 N.C. 89 0
+50 N.C. 90 - 4.7
43+12 + 1.6 90+77.11 - 6.2
44 N.C. *Negative (-) values equal landward retreat
45 N.C. Positive (+) values equal bluff slumping seawz
46 - 6.2
47 - 1.6 **NC = No comparison possible
-22-
TABLE IB
Vertical Elevation Differences and Horizontal Distances Between
First ~Si~nificant Nickpoint on Landward (South) Side of Profiles
Site
Elevation & Distance(ft)* Site
Elevation & Distanqe.(ft)*
10+00
11
12
13
13+74
14
15
16
17
18
19
20
20+32
21
22
23
24
25
26
27
28
29
30
31
32
'33
34
35
36+00
37
37+10
37+19
37+20
37+70
38
39
40
41
41+31
41+50
42
42+25
42+50
43+12
44
45
46
47
48
49
+0.1
+0.8
+1.0
-0.8
-1.2
-1.3
-1.6
-0.7
-1.2
-0.5
-0.4
-0.1
-0.4
-2.2
+ 2.0
+0.6
- 1.0
-1.2
-1.2
+ 0.5
+ 1.1
-0.1
-0.7
- 1.1
-2.7
+1.4
+0.4
-1.4
- 1.5
+1.2
-0.5
N.C.**
+ 1.1
- 0.2
N.C.
N.C.
N.C.
N.C.
N.C.
+ 2.9
- 2.2
N.C.
N.C.
- 0.2
N.C.
N.C.
N.C.
+0.1
+2.5
+2.1
-9.4
-4.7
-6.2
0
+4.7
+9.4
+1.6
-4.7
-3.1
-9.4
-7.8
-3.1
-7.8
+ 9.4
-1.6
- 6.2
+ 4.7
+ 4.7
-6.2
-14.0
- 6.2
-6.2
-4.7
-1.6
+3.1
-12.5
+1.6
-4.7
+1.6
-6.2
- 6.2
-12.5
+ 1.6
-17.2
+25.0
0
- 1.6
-25.0
-20.3
50 + 1.5 -22.0
51 N.C.
52 N.C.
53 + 1.9 -14.0
54 + 0.1 + 4.7
55 + 0.4 - 3.1
56+00 + 0.6 - 2.3
57 + 0.3 - 3.1
58 + 1.1 - 6.2
59 + 0.4 - 3.1
60 + 0.3 + 4.0
61 + 0.3 - 1.6
62 + 1.1 - 4.7
63 - 1.1 +18.7
63+84 N.C.
65 + 2.3 -12.5
66 N.C.
67 + 1.5 -18.7
68 + 1.4 -19.5
69 + 0.6 -10.1
70 + 1.9 - 7.8
71 + 0.7 - 7.8
72 + 1.6 - 9.4
73 + 2.3 -22.0
74 N.C.
75 + 3.6 -14.0
76 + 1.2 -10.1
77 + 2.3 -14.0
78 + 2.0 - 6.2
79 · - 0.1 0
80 + 0.2 0
81 + 3.7 -18.7
82 + 0.1 0
83 + 0.6 -18.7
84+00 + 0.2 - 1.6
85+00 + 0.1 - 1.6
86 + 0.1 0
87 - 0.4 + 4.7.
88 - 0.3 0
89 - 0.5 0
90 + 0.6 - 4.7
90+77.11 + 1.7 - 4.0
*Negative (-) values
Positive (+) values
**NC = No comparison
equal landward retreat
equal bluff.slumping
seaward
possible
-23-
for . March, 1974--April, 1975 as well as the horizontal
displacement of the nickpoints. This value may be the better
measure of actual bluff retreat since the LILCO profiles do
not extend to the top of the bluffs nor are they measured
to a common elevation above sea level. The extreme value of
retreat between nickpoints is 25 feet with concentrations in
the 5- to 10-foot range. These retreat values exceed those
observed in initial testimony based on four profile sites.
-24-
Implications of Bluff Retreat.Rates
Present retreat rates of the bluffs along and adjacent
to the LILCO Jamesport property average 5-10 feet per year,
and maximum of 22 feet per year. The plant site as illustrated
in public exhibits included in case 80003 is situated 900 feet
south of the March, 1974 shoreline and 500 feet south of the
100' contour representing the bluff crest between the shore-
line and the plant site. Using the average retreat value of
5-10 feet per year, erosion would bring the bluff crest to
the edge of the power station in 50 to 100 years.
Clearly, a situation in which coastal erosion would
reach the stage of undermining a nuclear power station would.
never be permitted to occur even if that station were no
longer active when this threatening stage was reached. What
would occur instead would be ever-increasing attempts by
both Federal, State and municipal governments and by LILCO
to construct jetties, seawalls and other protective struc-
tures to prevent this threat of undermining. Once the Corps
of Engineers has granted a permit to construct the jetties
as part of the intake channel there is a clear precedent
established to permit other types of necessary protective
structures to be built once the power station is construc-
ted. This precedent leads to two very obvious consequences.
1. Increased amounts of public and private monies
would necessarily have to be committed in the future
to prevent continuing erosion of the bluffs at the
Jamesport site.
2. Construction of any types of protective struc-
tures which would prevent the predicted erosion of
the Jamesport site bluffs would increasingly deplete
the sand supply capable of moving both on and off-
shore during and after storms and in the littoral
current system. Present erosion rates would increase
dramatically in areas adjacent to LILCO's Jamesport
property because of the retention of large amounts
of sediments by the structures which necessarily
would have to be built. It would be only specula-
tion, within the limits of present data, to suggest
the distances to which this increased erosion would
occur, what the degree of increased retreat rates
might be, and what public and private organizations
would bear legal responsibilities for the consequen-
ces of increased erosion beyond the limits of the
Jamesport site.
-25-
Sediment Sampling Data
Seven sediment samples were taken at four sites (which
coincide with four of the more than 90 profile lines) by
LILCO in June and October, 1974. The four sites (the numbers
of which relates to LILCO's survey lines) are 10+00, 40+00,
66+00 and 90+00. These numbers translate into the fact that
the four sediment sample lines lie 1,000, 4,000, 6,000 and
9,000 feet west of a zero survey point at the east side of
LILCO's Jamesport property. Site 40+00 represents a loca-
tion between two jetties which were formerly present along
this stretch of coastline. The seven samples taken at each
of the four sites were selected from the beach surface, mean
high water, mean sea level, mean low water and at water
depths of 6, 12, ~nd 18 feet.
Sieve Analysis
Each of the seven samples taken on both 1974 sampling
dates at all four sites were analyzed for grain size dis-
tribution using standard sieve techniques. A stack of several
sieves each having a screen mesh of diminishing dimensions
from the top to bottom of the sieve stack is shaken in a
mechanical shaker for a fixed length of time (usually several
minutes). The initial weight of the sediment sample is
measured before pouring the loose, dried sediment into the
top of the stack of sieves. After shaking for a given period,
the amount of material retained on each sieve is weighed and
this weight, in proportion to the total initial weight of the
sample prior to sieving yields a percentage value of that
sample retained by each diminishing sieve mesh opening. Thus,
an accurate percentage of each grain size range is determined
by this type of sieve analysis. In simplest terms, all
pebble sized grains remain near the top of the stack of sieves,
the medium-sized sand grains fall through each diminishing
mesh to about the middle of the stack, while the fine sands,
silts and clays fall to the lowermost sieves near the bottom
of the stack.
Because a sieve analysis characterizes sediment from
any type of environment (in this case, from the beach, the
intertidal zone and offshore out to 18-foot water depths),
it is a simple matter to then determine in what size range
the bulk of each sample lies from each site and environment.
Thus, one can show what the predominant grain size is, for
example, of a beach during calm waves versus during storm
waves. The latter represents more vigorous energy and typi-
cally coarser sediment makes up the bulk of beach deposits
under high energy conditions. As waves become calm, finer
grained sand can also accumulate and may predominate the
beach environment after post-storm recovery when sand moves
ashore to restore the typical convex-upward profile of non-
storm beach.
-26-
Results of Sieve Analysis
The results of the June and October, 1974, sediment
analysis by sieving are publicly available. The weights
and precentages of each grain retained by each sieve mesh
used in the analysis are available along with curves showing
cumulative percentages of all grain sizes in the samples.
Both cumulative curves and the raw weight data are difficult
to visualize in terms of sediment size distributions and,
in this present report, the data have been presented as
bar graphs (histograms), using LILCO's raw data. The follow-
ing grain size classes have been grouped and shown in the
histograms (Figures 5, 6, and 7):
(4-32mm) Pebbles
(1/2-4mm) Coarse sand to granules
(1/4-1/2mm)Medium sand
(finer than 1/4 mm) Fine to very fine sand,
clay
silt and
Figure 5 represents the grain size characteristics of
the beach for both the June and October, 1974, sampling
dates; Figure 6, those characteristics of samples taken at
mean high water, mean sea level and mean low water; Figure 7,
from water depths of 6, 12 and 18 feet. Note in each
histogram that the June samples are in the upper row of
histograms; October, in the lower row. Histograms are arran-
ged from east to west (right to left) along the line approx-
imating LILCO's survey base line for March, 1974. In
addition, the reader should observe that on each set of
histograms in Figures 5, 6 and 7, sample site 40+00 cor-
responds to the position between former jetties constructed
on the Levon property. In what follows, is a brief state-
ment of the interpretation of these h~stograms. The signi-
ficance of the data portrayed in these histograms is crucial
to judging the proposed sand bypass system by dredging from
the margins and from between the newly proposed jetties. It
also provides some insights into what grain sizes are
stable in the Jamesport coastal zone during the June and
October, 1974, sampling. The inadequancies of frequency
and distribution of sampling as done by LILCO will be dis-
cussed following the description of what the histograms show.
Beach Samples
Figure 5 shows that, in all but one sample (June beach
sample at site 40+00), medium grained sand is the predominant
sediment size for both the June and October, 1974, samples.
Coarse sand and granules dominate the June sample of beach
sediment taken from site 40+00 (between the former jetties).
Note also that the percent of pebbles is significantly higher
in samples from just east and west (sites 10+00 and 66+00) of
the former jetty site whereas at the westernmost sample site
BEACH SAMPLES
GRAIN SIZE DISTRIBUTION
[ Neve data from LILCO]
Oct.
1974
West t
site
[] ~ Pebaes
s~te
66*O0
& grsnulos (Jo4mm)
between former
jetties
5s
site
site
Figure 5. Sieve AnalFses of Beach
Sediments - Histograms
INTERTIDAL SAMPLES
Figure 6.
Sieve Analyses of Intertidal
Sediments - Histograms..
,4'
.4'
Figure 7. Sieve Analyses ~ Sediments from Water
Depths Of 6, 12 and 18 feet - Histograms.
-30-
(90+00) as well as at the site between the former jetties,
pebbles represent a minor constituent of the total beach
sample both for the June and October sampling dates. These
concentrations of pebbles on either side of the former jetties,
and predominance of granules to coarse sand in the June
samples between the former jetties, indicate that those
jetties (taken down to the mean low water in the early 1970's)
are creating an energy shadow. This energy shadow creates a
situation in which coarse sand to pebble size sediment can be
transported to those sample sites, but probably is not re-
moved during succeeding times of high wave energy.
The percentage of fine sand and finer sediment is vir-
tually the same minor value in all beach samples for both
dates. The inference to be made from this fact is that wave
action on the beach is of sufficiently high energy to winnow
out fine material from the beach and currents have carried
the fines elsewhere. As will be seen later in the descrip-
tion of Figure 7, fines are of more than a minor component
of the offshore samples taken from water depths of 6, 12
and 18 feet.
Intertidal Samples
Results of LILCO's sieving of samples from the four
sites at mean high water, mean sea level and mean low water
are presented in Figure 6. These histograms for both June
and October, 1974, show that fine sediment is virtually ab-
sent from all samples and reaches only 6% in two October
samples from between and just west of the former jetties
(sites 40+00 and 66+00). The important contrast between
this histogram and that for the beach samples (Figure 5) is
the minor amounts of medium sand in most of these intertidal
sediments. Medium-grained sand typifies .the bulk of the
beach samples shown in Figure 5.
In the June intertidal samples, pebble percentages in-
crease from mean high to mean low water at the east and west
end of the sampled area (sites 10+00 and 90+00) in contrast
to the opposite trend of decreasing sediment sizes from mean
high to mean low water between the former jetties (site 40+00).
The October, 1974, samples from the intertidal zone
(Figure 6) show c~nsiderable differences among s~mples sites
as well as'contrasts to the June Samples. Samples from sites
10+00 and 66+00 are nearly mirror images of one another. Note
that at site 66+00, the pebbles represent 75% of the sample
taken at mean low water. At site 10+00, the mean high water
sample has 75% pebbles. Interestingly, the mean low water
histogram at site 10+00 is nearly the same as the mean high
water histogram at site 66+00. This effect of mirror image
histograms between the two sites which lie east and west of
the former jetties confirms an energy shadow effect produced
-31-
by the jetties themselves. Because there are no available
data on wave conditions for the October sample data, a proper
interpretation of this energy shadow produced by the former
jetties is impossible. In fact, two completely different
interpretations could be made from the data, one of which
would be favorable to a sand by-pass system, one unfavorable.
The absence of recorded data on littoral current direction
and velocity during this sample period has yielded ambiguous
results.
This ambiguity is even more apparent when the sieve
analysis data for June and October are compared at site
40+00 where the former jetties had been constructed. Pebbles
dominate the June intertidal samples, whereas coarse sand to
granule sizes dominate the intertidal samples taken in
October. Higher energy waves apparently were prevailing
around the time of the June versus the October sampling
dates. Wave data are lacking to support this conclusion.
An entirely different interpretation is just as reasonable
with this lack of wave data. It is just as reasonable to
suggest, based on only the sieve analysis data here shown
in the histograms, that the dominance of pebbles between
the former jetties in the June sampling is a product of low
wave energy and the pebbles are simply lag deposits trapped
between the old jetties. The general similarities of the
October intertidal samples between the former jetties and
at site 90+00 support this second view since both sites are
dominated by coarse sand to granule size material. The pre-
sence of coarse sand to granules at those sites may be a
reflection of the maximum grain size which the October waves
were transporting during the sample period. The important
point to make here is, that a number of interpretations are
possible but, with the proper wave data which should accompany
sediment sample analyses, most of those interpretations could
be eliminated and a reasonable assessment could be made of
sieve data in terms of the value of a sand bypass system.
With the limited data available, no geologically reasonable
assessment is possible.
Offshore Samples
The results of LILCO's sieving of offshore samples are
shown in Figure 7. Samples at each of the four sites were
taken at water depths of 6, 12 and 18 feet (presumably below
mean sea level). Pebbles are virtually absent from all June
and October, 1974, samples except at depths of 6 feet be-
tween the former jetties (site 40+00) and at that depth at the
easternmost site (10+00) in the June samples. The large
quantity of pebbles (40% for June and 25% for October)
support the inference of entrapment of coarse sediment by
the former jetties. In contrast, fine sand and finer material
is not retained offshore between the jetties for the two
sample dates. Fine sediment is more abundant both east and
-32-
west of the former jetties, particularly in the October samples.
Thirty five percent fine material was collected in the October
sample at a depth of six feet at site 66+00. East of the
former jetties at site 10+00, medium sand represents the
bulk of all but one sample taken in June at the 12-foot depth
location. This is also true of the October samples from
site 90+00 and at two of the three depth positions at site
66+00. In contrast, coarse sand to granules and pebbles
dominate the June samples at site 90+00 and at water depths ·
of 12 and. 18 feet at site 66+00. If wave properties were
available for these sample dates, it might be possible to
show that a sediment bypass program for offshore sediments
(6- tolS-foot depths) could be successfully carried out.
However, ~he lack of such data, makes it unreasonable to spec-
ulate about the quantities of coarse materials in the off-
shore zone both between and west of the former jetties. It
is unreasonable because this quantity of coarse sediment is
considerably higher than quantities of similar sized materials
in the beach itself (Figure 5). This amount of coarse ma-
terial could be lag deposits below the limits of calm wave
agitation of the bottom sediment or it could be material just
previously removed by storm-waves from the beach. Correla-
tion of sieve data to beach profiles would be useful in this
case in as much as the profiles would be concave downward
following a storm and convex upward after a post storm recovery
of the beach by onshore transfer of bar sands. Unfortunately,
LILCO's June, 1974, sample data do not coincide with the
quarterly profile dates for that year and no sediment sample
date accompanies the October collection to indicate whether
or not sampling was carried out in conjunction with the
October, 1974, profiling.
Inadequacy of Sediment Sampling Program
In addition to the problems associated with the sediment
sampling data--namely, lack of data on wave characteristics
during sampling and apparent absence of time coordination
between sampling and profiling--other inadequacies of the
LILCO sieve analyses are also apparent; they are:
1. Data come from only four sample sites taken on lines
from the beach to water depths of 18 feet. These four
lines are perpendicular to the ll,000-foot long baseline
along and adjacent to LILCO Jamesport property. The
irregularity in the data indicatesthat four sample lines
cannot be used to characterize this coastal zone.
-33-
2. Sediments between the former jetties have grain dis-
tributions which differ from the other three sets of
samples implying jetty control on sediment taken at
site 40+00.
3. Variations among samples collected in June versus
those collected in October, 1974, suggest that the
periodicity of collecting is far too wide.
4. No sampling has been made of various parts of the
beach to allow for comparisons of grain size from mean
highwater toward the bluffs.
5. No sieve analysis data have been made available since
the October, 1974 sampling in contradiction to the
public statements by LILCO concerning an ongoing sieve
analysis program.
The available sieve analyses for 1974 are not themselves
adequate to support the proposed dredging and sand bypass
system from the west side of the proposed jetties to the east.
-34-
'EFFECTS OF FORMER JETTIES AT JAMESPORT SITE
Jetties were constructed by the summer of 1969 on
property then owned by Levon. The location of those jetties,
which extended 550 to 559 feet into Long Island Sound, is
generally the same as the 800-foot jetties proposed on either
side of the intake channel by Long Island Lighting Company
at the Jamesport Nuclear Power Station. Under an agreement
with the New York State Attorney General's Office, the owners
of that property removed by December 1, 1971, the upper sur-
face of these jetties to below the mean low water line at the
coast with a gradually increasing depth of the top surface
reaching six feet below mean low'water at the north (seaward)
end of the jetties. For most of their original length the
depth Of the top surface of these former jetties lies between
4.5 feet and 6 feet below mean low water. Because the foun-
dations of these jetties still remain just below the water
surface the structures continue having an influence upon
sediment transport in and out of and parallel to the shoreline.
LILCO's profile and sieve data from site 40+00 confirm this
control.
Thus, the effects of jetty construction at the James-
port site have already been tested and the influences of
those jetties will be examined below. It must first be
mentioned that LILCO's proposed 800-foot long jetties would
be built with these additional programs to be carried out.
1. LILCO acknowledges that the proposed jetties would
effect the littoral current and they have proposed a
sediment bypass method.
2. LILCO agreed-to begin a beach monitoring program
using profile data and sediment sample sieve analyses
to determine what erosive effects might result from
jetty construction. Their monitoring program was
begun in March, 1974. Comments and analyses of both
the profile data and sieve data have already been made
earlier in this report.
Because of the absence of wind and wave data to help
fully assess the values of the beach monitoring program,.
the remainder of this section will simply examine in a
qualitative way the effects on the shoreline at Jamesport
of the former jetties at this proposed construction site.
This qualitative evaluation leads to some specific observa-
tions and conclusions concerning the impacts which the pro-
posed LILCO jetties might have along the adjacent coastline.
The impacts of those jetties must be evaluated independently
of LILCO's proposed beach enrichment program because the
adequacy of that program, if based on data available from
the beach monitoring studies, cannot be properly assessed
for reasons given previously.
-35-
Aerial photographs are the simplest means of making a
qualitative assessment of jetty influences. A quantitative
assessment of coastal changes using aerial photographs is
beyond the scope and intent of this present report. Aerial
photographs available for qualitative comparisons are listed
in Table 2.
Date Flow~.
1966 (May 7 & 11)*
Scale 1"=1600'
TABLE 2
AERIAL PHOTOGRAPHS OF COASTAL ZONE -- JAMESPORT
index and Photo No. Available From
6526-994
-809
-848
-1006
Town Supervisor's
Office, Southold,
New York
1972 (May 6)*
Scale 1''= 1320'
2556x2398-34-823
-35-848
-36-851
-37-878
1974
(April 8 & 15)* 4028
2808-1-75
-76
-77
-79
2809-11-423
-424
-425
-426
-427
1961 (May 17)
ASA-4AA-53
70-17-196
-198
-200
-203
-205
-209
-21
-23
-25
-28
-30
-74
-76
Marine Resources
Council,
Hauppaugue,N.Y.
(over)
-36-
Table 2 Continued
Date Flown
1976
Index and Photo No.
AGC-67-1904
-1905
-1906
-66-1884
-1885
-1886
-65-1860
-1861
-1862
-1863
-64-1838
-1839
-1840
-63-1815
-1816
-1817
-62-1792
-1793
-1794
-61-1770
-1771
-60-1747
-1748
Available From
Marine Resources
Council, Hauppaugue,
N.Y.
Other aerial photographs available include 1947,.1961,
1969, 1970 from Department of Environmental Conservation,
Albany, N.Y., from the Marine Resources Council (Hauppaugue,
N.Y.) and from the U.S. Department of Agriculture. Office
(Riverhead, N.Y.).
*Purchased for this report from Lockwood, Kessler and Bartlett,
Syosset, N.Y. Original photo prints on file with this report
in Office of Southold Town Supervisor. All other copies of
report contain xerox copies of those prints. Scale and
accuracy of copies not that of print originals in Town Super-
visor's Office.
-37-
An average of 20 beach width measurements made on the
1966 aerial photograph (6526 51-1006) which shows the James-
port site with Hallocks Pond about in the mid portion of the
photograph (Figure 8),indicates beach width of about 180 feet
across the entire area. Minimum width values are about 120
feet and maximum beach width values are about 240 feet. The
important observation to be made on this 1966 photograph are
the general un~ormity of width across the entire area with
no abrupt changes in beach widths. The 1966 aerial photo-
graphs (Table 2) were taken prior to jetty construction on
the Levon property.
Shortly after construction of the Levon property jetties,
the abrupt changes in shoreline widths are readily apparent
on pho~ographs available at the Department of Environmental
Conservation (Albany, N.Y.). Aerial photograph (dated 1969),
ASA-2KK-10B was used to measure beach widths along a line
extending approximately 3,400 feet to both the west and east
of the jetties. Average beach widths to the west of the
jetties are 103 to 137 whereas to the east, widths average
34 to 69 feet. A Xerox reproduction of a photographic copy
of this 1969 aerial photograph is shown in Figure 9. Not
only is the sharp decrease in width apparent in the measure-
ment made on the 1969 aerial photograph east of the jetties,
but clearly there is a decrease in average beach width from
180 feet (in 1966) to 103 to 137 feet west of the jetties
(1969).
The aerial photograph for 1972 (2556 2398-35-848) is
copied in Figure 10. West of the jetties, average beach
widths are 160 to 240 feet; east of the jetties, widths
range from 40 to 120 feet.
Figure 11 is a copy of the print of aerial photograph
4028 2808-1-75 taken April 8, 1974. Average beach widths
west of the jetties are 66 feet; east of the jetties, beach
widths average 33 feet.
The beach width data cited above must be viewed as
indicating relative changes among the time period 1966
through 1974. The values are not absolute widths since tide
stage is not given (although can be determined) for each
date of photography. Despite this, it is clear that prior
to the construction of the jetties, the Jamesport beach was
~latively wide and relatively uniform. Once the jetties
were constructed, beach widths east of the jetties range
from 1/4 to 1/2 the average widths of the Jamesport beach to
the west. Tide stage does not differentially influence these
relationships unless there was a significant beach gradient
differential between the eastern and western beaches.
Equally as significant are the observations made abo~e that
beach width to the west of the jetties has decreased by about
25 to 33% of its original 1966 pre-jetty construction width.
-38-
Figure 8.
Copw of 1966 Aerial Photograph*
Along Jamesport Coastline.
-40-
Figure 10. Copy of 1972 Aerial Photograph*
Along Jamesport Coastline
Figure ~. CopL
J~mesport Coa$(
-41-
Figure 11. Copy of 1974 Aerial Photograph*
Along Jamesport Coastline
-42-
Significance and Implications of Aerial Photograph Comparisons
The importance of this qualitative analysis of beach
widths at the Jamesport site from 1966 through 1974 is of
major importance in ~udging the influence of jetties on an
environmentally fragile coastline such as gong Island's North
Shore. It indicates that jetty damage is not confined to
only one side of these structures. It confirms the fact that
littoral drift is not uniform in its flow direction but has
caused erosion both to the east and the west of these former
jetties. The data presented above for 1972 and 1974 confirm
that the erosive process is still active because the jetty
foundations remain no deeper than six feet below mean low
water. The most important implication of this analysis of
aerial photography lies in the fact that LILCO has not in-
dicated that any replenishment program is contemplated for
the portion of the Jamesport site to the west of the pro-
posed 800-foot jetties where erosion has increased since
.1.969 when the Levon jetties were in place.
The fundamental lack of wind and wave observations
coupled with both profile and sediment sample analyses is
the principal problem in attempts to predict outcomes of
coastal processes at the Jamesport site. One reasonably
qualitative prediction that is possible from the photograph
measurement data given above is that, with continued nar-
rowing of beaches both east and west of the former jetties,
the natural replenishment source will be tapped to re-
establish an equilibrium in this narrowing beach system.
That natural source of replenishment is sediment in the bluffs
themselves. Significant bluff undercutting and slumping has
occurred and can be expected to continue as long as this
deficit in beach material continues. Figure 12 is a map of
Long Island Lighting Company's Jamesport property showing
coastline width differences to the east and west of the
former Levon property jetties.
LONG ISLAND SOUND
Fi'gure 12.
Map of Long Island Lighting Company's Jamesport
Property Showing Coastline Width Differences to
East and West of Former Levon Property Jetties
-44-
ANALYSIS OF BOREHOLE DATA FROM EXCAVATION SITE FOR INTAKE
STRUCTURE AND CHANNEL
The plan map and cross section shown in Figure 13 is
taken from public information prepared for LILCO at the
Jamesport site. The map shows three borehole sites (J-11,
J-12, and J-13) which lie between the proposed jetties.
The sediment types in each of the three boreholes are shown
in the cross sectional view of the proposed intake channel
to be excavated. The excavated channel is to be 12 feet
deep at its mouth in Long Island Sound and 27 feet deep at
the face of the proposed intake structures at the shoreline.
LILCO proposed (in its Alternative A) to dump the excavated
sand and gravel portion of this removed material east of
their proposed jetties as replenishment material for those
beaches.
The borehole data indicate that less than half of the
sediment cored is coarser than silt and clay. In addition,
no sieve analysis is available to indicate what portion of
.the cored material listed as gravel, sand, sandy silt is
actually of mediu~ sand size and coa~rser. The available
sieve data analysed earlier in this report clearly shows that
sediments finer than medium sand are lacking (that is, have
been winnowed out by wave action) in the June and October,
1974, sediment samples.
The information shown in Figure 13 clearly indicates
that less than half of the excavated material to be dumped
from the channel site to the adjacent beaches will act as a
replenishment supply. In its total volume estimates of
400,000 cubic yards of sand and gravel to be available for
replenishment, the company has included excavated material
from the line of the diffuser system along with that to be
excavated for the intake structure and channel (Alternate A).
The amounts from the two excavations ha~e not been dis-
tinguished in the publicly available data. Clearly the bore-
hole data shown in Figure 12, suggest that some portion of
the dumped sediment will be quickly removed from the "re-
plenished'' beach by the winnowing action of waves and wind.
This will add a new quantity of fine sediment to the Sound
waters increasing turbidity, adding sediment to embayments
and to Mattituck Inlet, as well as causing fine sediment to
build up locally offshore in Long Island Sound. A more
detailed grain size distribution analysis is clearly needed
before permission can be granted to LILCO to dump the sand
and gravel portion of the excavated sediment on the adjacent
beach.
The fact that more than half of the sediment cored down
to the base of the proposed excavation contains silt and
clay, and that the channel will act as a natural sediment
and pollutant sink as suggested earlier in the sediment and
profile data from between the former jetties~ a potential
environmental hazard clearly exists. Fine sediments which
pipes
~J12
Jll
t
/-Jetty
beach replenishment area
Intake
structures
o ~ 400 4oo ~x) IoooP~T
BORING PLAN AND PROFILE FOR INTAKE CANAL
LILCO Jarnesport Nuclear Power Station
0 500'
....... Jll 113
L-pumphouse
north wall
~,--.existing bottom
112
' ~--~na, sandy gravel,
gravelly sand, silty sand ~ silt
clay
Figure 13. Map of Borehold Sites Between Proposed Jetties
and Sediment Type Recovered from Borings.
-46-
are not oxidized cause the precipitation of some radioactive
materials from solution, even where concentrations in the
solutions are on the order of a few parts per million. Water-
flow through fine sediments in a chemically reduced state
allow pick-up and concentration of these small amounts of
radioactive material by precipitating them out of the water.
The proper conditions are all here at the Jamesport site to
allow such a build-up to be initiated and continue through
time; namely, waste waters bearing low concentrations of
radioactive material, fine sediments, and chemical unoxidized
conditions beneath the intake channel surface. Such condi-
tions most probably exist elsewhere beneath the surface
sediments on the Sound floor as well. This potential envir-
onmental hazard effecting burrowing organisms including shell
fish as well as man clearly demands thorough investigation.
No mention of this potential problem was made in the Final
Environmental Impact Statement for the Jamesport site.
-47-
CONCLUDING STATEMENTS
The necessity for this report is an enigma. The Town of
Southold invested in the preparation of this report in which
the data analyzed have been available to Federal and State
Authorities as provided by Long Island Lighting Company.
LILCO has fallen far short of providing the bulk of
the essential data and has provided minimal interpretations
about its significance to impacts of jetty construction at
the Jamesport site. It is part of the mandate for Federal
and State institutions to be aware of types of data needed and
to require an applicant to display the interpretations and
implications of such data. Further, federal regulatory
agencies, such as the Department of the Army, Corps of
Engineers, have both the staff and ability to independantly
evaluate data of the type analyzed in this report. Also,
such agencies must be presumed to be independent of both
private and corporate pressures in making their independent
evaluations.
The summary of .findings, included at the beginning of
this report .and developed in detail within the body of the
text, clearly shows that the data available do not support
the intent for which they were gathered. In addition, it
has been stressed that the data are inadequate to make pre-
dictive judgments concerning impacts of the proposed jetties
on coastal erosion because they are not coupled in time
(profiles and sediment sampling, for example, should be
carried out concurrently) nor linked to the essential wave
characteristics prevailing during data ao~uisition. It is
abundantly clear that the Corps of Engineers is not in a
position to permit jetty construction because of missing
data or ambiguities inherent in the limited ~ypes .of data
presented. The recommendations made here on behalf of the
Town of Southold, New York, are stated at the beginning of
this report. They specify the types of information which
are essential in determining the validity of the applicant's
(LILCO) request for a permit to construct jetties at the
Jamesport site. This report demonstrates some of the im-
portant reasons why that application should be rejected in
its present form.
-48-
RESUME
DOUGLAS GLAESER Date of Birth:
Consultant Geologist July 5, 1934
& Adjunct Associate Professor
Department of Geology, Duke University
Certified Professional Geological Scientist No. 4124
Office Address and Telephone Numbers
36 Riverside Drive
New York, N.Y. 10023
Duke University Marine Laboratory
Beaufort, NC 28856
Duke University Geology Dept.,'-Durham,
NC 27708
(212) 580-3460
· (919) 728-2111
(919) 684-2206
Consulting~ Research and Teaching Activities
Geologic assessments, coastal zone and continental shelf; middle
~$d north A~lantic, eastern United States.
Sedimentologic-stratigraphic frameworks, Devonian clastic wedge of
Central Appalachian basin and Triassic basins of eastern
United States
Depositional models applicable to hydrocarbon and uranium accumu-
lations.
Applications of modern coastal and fluvial systems to ancient sedi-
mentary analogues
Coastal processes and nearshore environments
Tectonic control of barrier island distribution
,Graduate and undergraduate courses taught: Sedimentology, Stratigraphy,
Geological Oceanography, Coastal Processes, Pleistocene Geology,
Geomorphology, Physical and Environmental Geology
Previous Positions
Associate Professor (1974-1976)
Dept. Earth and Planetary Sciences
City College of City Univ. of N.Y.
New York,. N.Y. 10031
Staff Geologist, Penna. Geological
Visiting Assoc. Professor (1973-1974)
Dept. of Geology
Univ. of North Carolina
Chapel Hill, N.C. 27514
Survey, Harrisburg, PA 17120 (1961-1973)
Publications
Twenty-eight articles, monographs and abstracts (Listed~on pages attached)
References
Dr. Orrin H. Pilkey
Department of Geology
Duke University
Box 6665 College Station
Durham, N.C. 27708
Dr. John M. Dennison
Dept. of Geology
Univ. of North Carolina
Chapel Hill, N.C. 27514
References (continued)
Dr. O.L. Franke
Dept. of Earth & Planetary Sciences
City College of City Univ. of N.Y.
New York, N.Y. 10031
Dr. John Conolly
ERA North America
200 Railroad Ave.
Greenwich, CT
Academic Background and Degrees
Franklin and Marshall College
B.S. in Geology
Miami University
Graduate Research Assistant
Graduate Tuition Fellowship
Northwestern University
Ph.D. in Geology
Curatorial Assistant
California Exploration Company Scholarship
Research Grant-In-Aid, American Association of
Petroleum Geologists
Elected to Sigma Xi
Dissertation:
"Provenance, dispersal and depositional environments
of Triassic sediments in the Newark-Gettysburg basin
E.C. Dapples, Supervisor
Invited Lecturer at Colleges and Universities
Williams College
University of North Carolina, Chapel Hill
Rutgers University, New Brunswick
Indiana Unversity of Pennsylvania
Dickinson College
S.U.N.Y., Buffalo
Duke University
Duke University Marine Laboratory
Brooklyn College, C.U.N,Y.
Marine Sciences Laboratory, Univ. of North Carolina
Cleveland State University
'1963,
Professional Memberships
Geological Society of America (Fellow)
American Association of Petroleum Geologists
Society of Economic Paleontologists and Mineralogists
International Association of Sedimentologists
Association of Professional Geological Scientists
1952-1956
1956-1958
1957-1958
1956-1958
1958-1961
1964
1958-1959
1959-1961
1960
1961
1965, 1970
1970, 1977
1971
1973
1973
1974
1975, 1977
1975, 1977
1976
1976
1977
PUBLICATIONS
J. Douglas Glaeser
Glaeser, J.D., 1962, Procedure for quantitative description of detrital
sedimentary rocks: Proc. Penna. Acad. of Science, V. 36, pp. 213-
217.
· 1963, Catskill reference section and its correlation to
other m~asured surface sections in northeast Pennsylvania, pp. 52-
61: in Shepps, V.C., ed., Symposium on Middle and Upper Devonian
stratigraphy of Pennsylvania and adjacent states: Penna. Geol.
Survey Bull. G-39, 301 pp.
Frakes, L.A., Glaeser, J.D., Wagner· W.R. and Wietrzychowski, J.F.,
1963,' Stratigraphy and structure of Upper and Middle Devonian
rocks of northeastern Pennsylvania: Guidebook 28th Annual Field
Conference of Pennsylvania Geologists· 44 pp.
Glaeser, J.D., 1963, Lithostratigraphic nomenclature of the Triassic
Newark-Gettysburg basin: Proc. Penna. Acad. of Science· V. 37,
pp. 17~-188.
, 1964, Sediment dispersal interpreted from composition
and texture distributions in the Triassic Newark-Gettysburg basin:
Geol. Soc. America, Special Paper 82, p. 73.
, 1966, Provenence, dispersal and depositional environments
of Triassic sediments in the Newark-Gettysburg basin: Penna. Geol.
Survey Bull. G-43, 168 pp.
, 1967, Bedding-plane slips, wedge faulting and facies
changes in the Parryville syncline, Carbon County, Pennsylvania:
Proc. Penna. Acad. of Science, V. 40, pp. 95-98.
· 1967, Catskill stratigraphy at the Lehigh Gap reference
section and its relation to type locations in northeastern Penn-
sylvania: Geol. Soc. America, Special Paper 115, p. 266.
· 1968, Absence of Pocono Formation at Elk Mountain,
Susquehanna County, Pennsylvania: Proc. Penna. Acad. of Science·
V. 42, pp. 187-189.
· 1969, Geology of flagstones in the Endless Mountains
region, 'northern Pennsylvania: Penna. Geol. Survey Information
Circ. 66, 14 pp.
, 1969, Marginal marine deposits in Upper Devonian Cat-
skill Formation, northeast Pennsylvania: Proc. Penna. Acad. of
Science, V. 43, p. 14.
· 1970, Correlation of Catskill sedimentary environments
and its economic significance: Geol. Soc~ America Abstracts with
Program, V. 2, no. 1, p. 21.
Glaeser, J.D., (in press), Global distribution of barrier islands in
terms of tectonic setting: Journal of Geology.
, (in preparation), Slope sediments in Devonian of Central
Appalachian basin; source and reservoir deposits: Joint AAPG/SEPM
Continental Slope Symposium, 1978.
and Smith, P.C., 1977, Assessment of the geologic infor-
mation of New York State's coastal zone and continental shelf and
its significance to petroleum exploration and development: New
York Stat~ Science Service-Geological Survey, New York State Ed-
ucation Department, Albany, 261 pp, (Vol. 1), plus appendix and
bibliography (Vol. 2).