HomeMy WebLinkAboutInvestigation of Water Resources June 1967 TOWN OF SOUTHOLD
SUFFOLK COUNTY, LONG ISLAND,N.Y.
INVESTIGATION
OF
WATER RESOURCES
JUNE 1967
The preparation of this report w~s financially aided
through a federal grant from the Department of Housing
and Urban Development, under the Urban Planning Assistance
Program for the Bureau of Planning Administration, New
York State Office of Planning Coordination. It was
financed in part by the State of New York.
MALCOLM PIRNIE ENGINEERS.
226 Westchester Avenue
White Plains~ N.Y. 10604
SECTION
me
II.
III.
IV.
V.
VI.
VII.
VIII.
IX.
NO.
1
2
5
6
7
TABLE OF CONTENTS
INTRODUCTION
GENERAL CONDITIONS
WATER SYSTEMS AND WATER USE
GEOLOGY
HYDROLOGY
AVAILABILITY OF FRESH WATER
PROTECTION OF GROUND WATER F~ESOURCES
FISHERS ISLAND WATER RESOURCES
CONCLUSIONS AND RECOMMENDATIONS
FIGURES
Location Map
Rainfall - Cutchogue 1949-66, incl.
.~Typi~cal Geohydrological Section
Water Table Contours
Water Levels in Wells S6558 and
S6780 ( Area A) - 1949-66, incl.
Water Levels in Wells S65~2 and 'S652~
(Area B) 1949-66, incl.
Water Levels in Wells S16787 ( Area D)
and in S16783 (Area C) 1958-66, incl. ·
PAGES
1-6
7-14
15-22
23225
26-31
32-38
'39i45
46- 51
52-57
FOLLOWING
PAGE~
?
10
29
28
31
PLATE
A
B
C
D
.PLATES
Large Scale Map of Southold
RepPoduction of Plate 1 of USGS-W.S.
Paper 1619-GG - Surficial Geolggical
Map of Southold
Reproduction of Plate 3 - USGS-W.S.
Paper 1619-GG - Map of Southold showing
Location of Wells and Position of the
Water Table in July 1959
Reproduction of Plate 2 of USGS-W.S.
Paper 1619-GG - Geohydrologic Sections
in Southold
IN BACK
COVER POCKET
TOWN OF SOUTHOLD
SUFFOLK COUNTY, LONG ISLAND,
NEW YORK
1
INVESTIGATION OF WATER
RESOURCES
JUNE 1967
I. INTRODUCTION
The preparation of this report for the New York State
Office of Planning Coordination was financially aided through
a Federal Grant from the Department of Housing and Urban De-
velopment, under the Urban Planning Assistance Program f~r the
Bureau of Planning Administration, New York State Office of
Planning Coordination. It was financed in part by the State
of New York, by the Town of Southold, and by the Village of
Greenport.
Purpose and Scope
The principal purpose of this investigation and study
was to provide information on the water resources of the Town
of Southold in connection with the overall planning work under
the Urban Planning Assistant Program for the Town.
The following subjects were investigated and are dis-
cussed in the report:
(a) Available water resources and the quantity of
water that may be obtained from the sources.
(b) Past and present water usage in various parts
of the Town.
(c) Estimates of probable future water consumption
and effects of land usage on available water
resources.
(d) Evaluation of various land use proposals, as re-
lated to available water.
(e) Consideration of methods for protecting and devel-
oping the water resources of Southold~ as related ~
to plans for future development.
The studies included field investigations of surface and
underground conditions and a review and analysis of data ob-
tained from previous investigations and reports. Information
obtained during the investigations from records and operating
experiences of the Greenport Water System and data obtained
from representatives of the U. S. Geological Survey, the New
York State Water Resources Commission, Suffolk County, the
Town of Southold, and from others familiar with local condi-
tions were yery helpful in connection with the studies.
Field investigations included observations throughout
the town related to agricultural,' residential, and business de-
velopments and to public and private water supply and sewage
disposal facilities. Visits were made during and after periods
of heavy rainfall to observe the extent of surface ponding
and run-off~ and during dry periods when there was maximum
use of water for irrigation. The character of surface soils
and underlying materials was investigated by sampling and
observing samples of materials obtained from well drilling
operations and from materials exposed in excavations.
Relationship of Water Resources to PlanninK
The sole source of water for the Town of Southold is
ground water, replenished each year by a relati~ely small part
of the rain which falls upon the area within the Town. A
large portion of the available ground-water is used for irri-
gation~ and the supply of ground-water that may be withdrawn
safely is limited to less than twice the total amount that is
used at the present time. For these reasons, the availability
of water is a major factor in sound planning for the future
development of Southold. In certain sections of Southold,
much greater quantities of water can be withdrawn than from
o'ther sections without contaminating the fresh water resources
with salt water. 'This fact must be considered in connection
with future planning.
Previous Investigations and Reports
There is a wealth of information available as to geolog-.
ical, hydrological, and ground water conditions in Long Island,
in Suffolk County an~ in'the Town of Southol~. Two of the
most recent and most significant reports covering Southold
ground-water conditions are the following:
"Hydrology of the Shallow Ground-Water Reservoir
of the Town of Southold, Suffolk County, Long
Island, New York": New York State Water Resources
Commission Bulletin GW-45 (Hoffman, J.F., 1961)
"Geology and Ground-Water Resources of the Town of
Southold, Suffolk County, New York": Geological
Survey'Water-Supply Paper 1619 - GG (Crandell, H.C.)
The two reports present results of investigations of
the U. S. Geological Survey in cooperation with the Suffolk
County Board of Supervisors, the Suffolk County Water Author-
ity, and the New York State Water Resources Commission. They
are part of an overall and continuing appraisal of ground
water conditions on Long Island which was commenced by the
Uo S. Geological Survey in 1932o
Both of the above reports contain much information on
existing wells, elevations of ground-water, and geological
and hydrological data. They provide an excellent review of
results of previous studies and reports. The plates in these
two reports showing numbered well locations throughout the
Town and contours and profiles showing elevations of ground
water relative to mean sea level are of great value in con-
nection with estimating the availability of fresh water in
various parts of Southold. Some of these data are reproduced
herein.
The following recent reports also are of interest in
connection with the water supply situation in the Town.of
Southold:
"Engineering Report on Water Supply - Village of
Greenport - February 1964" - By Holzmacher, McLendon
& Murrell.
"Water Resources of the Town of Southampton, Suffolk
County, New York - December 1966" -By Behre Dolbear
& Company.
"Pollution a~ Water Supply of the Town of Southampton -
January 1967" - By John P. Mahoney, Consulting Engineers.
The first of the above three reports contains mu~h in-
formation concerning the property and operations of the water
system of the Village of Greenport,'which serves water'to the
Village and adjacent areas. The second and third are of inter-
est because the water situation in the Town of Southampton,
which comprises a large portion of the South Fork peninsula,
in many respects is similar to the situation in Southold in
the North Fork peninsula. °
Current Investigations and Stu~es
The cooperative studies of U. S. Geological Survey and
the New York State Water Resources Commission are continuing
studies~ and additional data on underground water conditions
and withdrawals throughout Long Island are collected each year.
The Long Island District Office of Division of Water
Resources of the New Y6rk State Cbnservation Department is at'
6
present conducting an interim water study of the Nassau-
Suffolk region in connection with a long-range planning
study, conducted by the New York State Office of Planning
Coordination.
Two additional interrelated investigations and studies
are underway which will provide much information on ground-
water resources in Suffolk County.
One of these includes the construction of some 14 deep
test wells, some of which will extend into bed rocks'. Two
of the wells will be located in Southold along North Ro~d,
one north of Cutchogue, and one northwest of the Village of
Southold. This investigation is of particular interest, inas-
much as very meager data exist on subsurface conditions in
Southold below the existing irrigation and municipal wells,
which are not very deep.
The other investigation is a comprehensive water supply
study for Suffolk County, financed by the State under its grant
program for water supply planning.
II. GENERAL CONDITIONS
Location and Extent
As shown on Figure l, the Town of Southold comprises
the easterly 20-mile portion of the northerly peninsula,
known as the North Fork, at the easterly end of Long Island.
It also includes Robins Island in Peconic Bay and Gull, Plum,
and Fishers Islands in Long Island Sound. The study area in-
cluded in this investigation consists of the peninsular por-
tion of the Town of Southold, which has an area of 42'.9 square
miles and Fishers Island, which has an area of 4.2 square
miles. Fishers Island is located about ll miles northeast from
Orient Point and 7 miles southeast from New London.
For convenience, the water situation in Fishers Island is
discussed separately in Section VIII of this report. In the
remainder of this report the mainland or p~ninsular portio~ of
the Town will be referred to as "Southold,"and Fishers Island
will be designated by name ....
Geographical Features
Southold is almost entirely surrounded by salt water. In
general, the higher portions are adjacent to or near Long
Island Sound and rise from 50 to 150 feet above sea level. The
land slopes southerly for the most part toward Peconic, Southold,
and Gardiners BayS. Southold has no surface streams or lakes
CONNECTI CUT
NEW YORK
LONG
NEW
JERSEY
QUEENS
CO.
KINGS *
NASSAU ~.oN 6
CO.
SUFFOLK
CO.
NEW
soUND
iSLAND
TOWN
OF SOUTHI
isLAND ,
o~
oG~I~
~ERS
ISLAND
GARDINtR$
5 5 I0 15 20
SCALE IN MILES
TOWN OF SOUTHOLD
LOCATION MAP
8
of appreciable size, but there are a number of fresh water
ponds~ some of which are a source of water for irrigation.
Much of the land is open land, suitable for cultivation.
There are a number of low wet areas and salt water marshes.
Most of these are located adjacent to the numerous salt water
inlets along the southerly shore of the peninsula.
Three salt water inlets (Mattituck Creek, Hashamomack Pond,
and Dam Pond) and adjscent'marshland~ and ~inlets'a~vide the'penin-
sula into four separate island-iike hydrological areas. These
areas, which are designated from west to east as Areas A, B,
C, and D in Geological Survey Water Supply Paper 1619-GG,
are considered separately in connection with estimating the
potential yield of underground water, because areas for re-
charge and ground-wate~ levels in each are different.
There are two small peninsulas, Little Hog Neck and Great
Hog Neck~ which extend southerly from the main 'Peninsula
and are separated from it b~' sal~ water inlets and marsh~s.
These also must be considered separately in connection with
availability of ground-water.
There are a number of attractive beaches along the souther-
ly irregular shore line of Southold. These beaches and the
fact that the area provides excellent natural facilities for
boating and bathing, have resulted in the development of many
areas along the south shore for seasonal and permanent homes.
There are a few such developments along the northerly or Long
Island shore line. However, 'the rugged nature of the~terrain
and the fact that there are fewer favorable boat anchorages
and attractive beaches has limited recreational developments
along this shore line.
Plate ~ in the pocket in the back cover of this report
is a map of Southold upon which the developed areas of Southold
are shown. The base map was prepared by Raymond and May,
planning consultants for this project. This map.shows the
limits of the'four hydrological areas A~ B, C, and D, and Little
Hog Neck and Great Hog Neck, which are described above.
Climate
Southold has a mean annual temperature of about 50 degrees
and an average rainfall of about 45 inches per year in the
western and central portions, in accordance with long-term
records at the Cutchogue Station. Shorter term records at
Orient Point, East Marion~ and the Greenport Power House indi-
cate that average yearly rainfall is about 10 per cent lower
than at Cutchogue. Rainfall is generally heavy in the fall,
winter, and spring months and much less during the summer months.
Yearly rainfall records at the Cutchogue Station from
1949 to 1966, inclusive, are shown on Table 1. This shows that
total rainfall at Cutchogue in 1965 was only 26.7 inches and
that the average for 1963, 1964, and 1965 was only 31.7 inches.
During these three years ~ record low rainfall was experienced
in many parts of the.Northeast.
TABLE 1
Annual Rainfall Records - Cutchogue Statioo
1949 - 1966~ Inclusive
'Year
Rainfall
In Inches
1949 45.21
1950 53.15
1951 60~50
1952 Record not complete
1953 51.18
1954 41.68
1955 35.15
1956 44.96
1957 33.46
1958 5t.47
1959 41.39
1960 38.12
1961 '41.38
1962 40.89
1963 33.16
1964 35.45
1965 26.68
1966 33.33
Figure 2 shows graphically rainfall at Cutch0gue Station
by years and by months from 1949 to 1966, inclusive.
Monthly and yearly rainfall records from 1960 to 1966,
incl¼sive, at the Greenport Power Plant.and at the East Marion
Well Field are shown on Table
70 FIGURE NO. 2
70
6O
b.J 50
-r
Z
Z
~' 40
0
Z
Z
Z
-r-
I--
Z
0
$0
2O
I0
0
I0.0
5.O
0
1950
1951 1952 195:5 1954 1955 1956
1958
1959
1960 1961 1962
1964 1965
60
5O
4O
:5O
2O
I0
0
I0.0
5.0
1967 1968
ll
TABLE 2
RAINFALL RECORDS - GREENPORT AREA - 1960 - 1966,
INCL.
January
February
March
April
May
June
July
August
September
October
November
December
Total
January
February
March
April
May
June
July
August
September
October
November
December
Total
GREENPORT POWER HOUSE STATION
1960 1961 1962 1963 1964 1965 1966
3.87 1.70 4.50 3.12 4.61 1.18 3.34
5.56 3.14 3.45 3.06 3.65 2.67 3.87
1.96 3.95 2.56. 3.45 2.49 1.92 2.15
2.82 7,04 3.82 .47 6.54 3.36 1.36
2.58 ~.48 .83 3.85 1.31 2.01 6.31
2.05 1.49 3.25 4.35 1.77 1.93 1.67
5.25 2.28 1.45 2.68 3.~4 2.94 .96
.98 4.13 6.11 2.96 1.32 2.95 1.89
9.09 5.72 3.72 2.12 3.09 1.93 5.12
2.37 2.66 4.76 .14 4.99 2.03 3.07
3.09 3.01 5.67 6.40 2.64 1.37 3.71
3.67 3.14 1.89 2.74 5.46 1.56 3.18
43.29 42.74 42.01 35.34 41.81 25.85 36.63
EAST MARION WELL FIELD
1960 1961 1962 1963 1964 1965 1966
2.94 2.74 5.55 3.12 4.46 1.10 3.09°
5.90 3.83 3.45 3.06 3.58 2.74 3.46
1.75 4.22 2.56 3.45 2.57 1.28 2.21
2.70 8.25 3.64 .47 6.11 3.42 1.71
2.84 5.52 1.18 3.85 1.30 1.99 6.55
1.75 2.00 4.45 4.35 1.56 1.46 1.58
6.84 2.09 .62 2.68 4.29 2.37 .95
1.!0 4.10 5.42" 2.96 0.82 2.13 1.92
9.57 9.89 1.87 2.12 3.27 1.62 4.86
3.21 2.94 5.01 .13 5.10 2.05 3.28
3.20 3.46 5.33 5.84 2.71 1.41 3.70
3.94 2.92 1.90 2.46 5.37 1.02 3.16
45.74 51.96 40.98 34.49 41.14 22.59 36.47
Historical Development
The development of Southold dates back to early in the
17th'century. It is believed that the first settlers were
Englis~nen who came to Southold by way of New Haven. The
early settlers cleared land and raised principally grain and
forage crops. Since that time, agriculture has been an im-
portant factor in the economy of Southold. Early in the 19th
century, shipping and whaling were developed to a considerable
extent. In 1848, the Long Island Railroad extension to Green-
port was completed and the Village became the important mari-
time center on a combined railroad and shipping route between
New York and Boston. The Village at present continues to be
a center.for commercial and recreational fishing activity.
The main factor in the economy of Southold is agriculture,
and this situtation probably will continue for many yeats. Topo-
graphy, climate, and soil conditions are favorable for produc-
t$on of vegetables. Conditions are particularly suitable for
large scale potato growing and also, to a lesser degree, for
raising such crops as cauliflower , cabbage, and B russel sprouts.
Another factor in the economy of Southold is the summer
resident and tourist trade. This will continue to expand as
the Long Island limited access highway system and the residen-
tial and industrial areas of western Suffolk County are extend-
ed eastward.
There are a number of unincorporated .communities in
13
Southold. The principal center of population is the in-
corporated Village of Greenport. From the westerly border
to Orient Point~ the unincorporated communities are: Mattituck,
Cutchogue, New Suffolk~ Peconic, Southold, East Marion, and
Orient. The railroad and/or main highway pass through each
of these communities except New Suffolk, which is lo~ated 6n
a peninsula in Peconic Bay.
The following tabulation lists the U. S. Census Popula-
tion of Southold and of the Village of Greenport, from 1910
to 1960, inclusive.
TABLE 3
U. S. CENSUS POPULATION FIGURES
TOWN OF SOUTHOLD AND VILLAGE OF GREENPORT
1910 1960, iNCL.
Town of Village of
Year Southold* Greenport
~910 10,577 3,0~9
1920 10,147 3~122
1930 11,669 3,062
1940 12,046 3,249
1950 11,632 3~028
1957 1R,607 2,645
1960 13,295 2,608
* Includes the Village of Greenport
It is estimated that the present permanent population
of th~ Town is approximately 16,000 and that there are about
2,500 persons residing in the Village of Greenport. It is
also estimated that the average population of Southold during
the three sumner months is approximately 32,000 persons.
15
III. WATER SYSTEMS AND WATER USE
General
The water system owned and operated by the Village
of Greenport is the only public water system in Southold.
This system provides fresh water for domestic use and fire
protection service in areas within and adjacent to the Village.
There are also a few small private water systems which supply
water to groups of homes. Most of the homes and business
establishments that are not supplied by the Greenport system
obtain their water from small individual driven wells.
Water used for irrigation comprises a major part of the
water withdrawn each year from the ground. Most of the irri-
gation water is from ~rilled wells from four to twelve inches
in diameter and from 15 to 150 feet deep.
Greenport Water System °
In 1898, the Village of Greenport acquired the small water
system of the Greenport Water Company..The Village system has
been expanded since that time to supply developed areas within
and adjacent to the Village. The franchise area of the Village
system prior to 1958 extended from Hashamomuck Pond easterly
to Shipyard Lane in East Marion~and from Long Island Sound to
Greenport Harbor.
In 1958~ the Village purchased the system of the North
Fork Water Company. It supplied water to built up portions
of the unincorporated village of Southold. Its franchise
area extended from Peconic Lane east to Hashamomuck Pond
and from Long Island Sound to Peconic Bay. At that time,
the Greenport system supplied about 1,000 consumers and the
North Fork Water Company supplied about 280 consumers.
The original well field of the Village of Greenport,
designated as Well Field No. 1, was adjacent to the Power
Plant at Moores Lane within the Village. The use of the
No. 1 Well Field for'water supply was discontinued many years
ago because of excess chlorides. It is now used for cooling
water at the Power Plant. The water is returned to the under-
ground ~upply. Later, additional wells were drilled at Well
Field No. 2 on Moores Lane, about 2,000 feet north of the
Power House and at Well Field No. 3, near the intersection
of Moores Lane and North Road. As the system was expanded and
withdrawals of water from Well Field Nos. 2 and 3 increased,
a number of wells were developed in the East Marion area. This
was necessary to avoid excessive withdrawals from the Moores
Lane well fields. Well Field No. 5 on South Harbor Avenue in
the Village of Southold is the field that supplied the North
Fork Company, and it is in use at present. Recently, two new
wells were developed north of Middle Road, near Norton's Lane
in Southold. These wells have been connected to the Greenport
:)
and North Fork systems. They supplied about 54 per cent of
the water in 1966.
Plate A shows the location of the six well fields des-
cribed above. It also shows the ~ocation of the six-inch
and larger water mains in the Greenport system, includinz
those purchased from the North Fork Water Company in 19~6
and the Connecting mains between the two systems which were
constructed recently. The easterly and westerly limits of
the franchise area of the Greenport system is also shown on
Plate A. A plan for extending the system easterly is'under
consideration.
Table 4 below shows the total average daily water pump-
age in gallons in the Greenport system from 1957 to 1966,
inclusive.
Year
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
TABLE 4
AVERAGE DAILY WATER PUMPAGE
GREENPORT WATER SYSTEM
Gallons Per
Day
440,000
410,000
400,000
440,000
450,000
480,000
510,000
502,000
481,000
610,000
l?
Maximum monthly water consumption occurs during the
s~nmer months and the daily average during maximin months
is about double the yearly average. Maximum daily consump-
tion is about three times the average daily consumption for
the year.
Table 5 below lists the number of actiYe services and
fire hydrants~ the quantity pumped in million gallons, and
the percentage increases during the past ten year period.
18
TABLE 5
GROWTH OF GREENPORT WATER SYSTEM
Active Services
Fire Hydrants
Water Pumped
195~ 1966 Increase Increase
973 1650 677 70
166 322 156 94
133 mg 222 mg 89 mg 67
In the early part of the past ten year period,
the Village
sold some water for farm irrigation, but practically no Village
water is used for farm irrigation at this time.
It is estimated that present p~mpage per service averages
about 350 gallons per day and that pumpage per person averages
about 100 gallons per day in the Greenport system.
Domestic Water Use From Private Wells
About 10~000 permanent residents~in Southold~ not
supplied by the Greenport System, use an estimated average
of 70 gallons per person per days or a total of 700~000
gallons per day. Some 15~000 summer residents use an aver-
age of 80 gallons per day for two months, or a total of
about 72~000,000 gallons per year. This is equivalent to
an average of 200,000 gallons per day for every day in the
year. The permanent and summer residents not supplied by
the Greenport Water System obtain their water from individu-
al wells.
19
Water Used For Irrigation
For many years, Southold producers of potato~s, cauli-
flower, and other'vegetable crops have utilized spray irri-
gation to supplement rainfall during an average period of
16 weeks each sun~er.
The amount of water used varies with the weather pattern
and soil condition. On the average, best results are obtained
when the ground receives the equivalent of about one inch of
rainfall per week. About one half of this generally is con-
tributed in the form of rainfall and the remainder by Spray
irrigation from water pumped from shallow wells. These extend
into the fresh water that is stored in the sand and gravel
under the top soil throughout a large portion of Southold.
2O
Most of the producers of vegetable crops have become
experienced in the e~onomical use of irrigation. It is
estimated that during an average season, water used for irri-
gation varies from about 150,000 to 200,000 gallons per acre
per year. At present, about 12,000 acres of vegetable crops
are irrigated each year and the average amount of water with-
drawn for irrigation is about 2,000 million gallons~ equivalent
to about 5.5 million gallons per day for each day during the
year.
Total Water Withdrawal In Southold
As shown in Tables 4 and 5, the total pumpage of water
in the Greenport System in 1966 was 222 million gallons, or
an average of about 600,000 gallons per day. The estimated
water withdrawn for irrigation was about 2,000 million gallons,
or an average of 5,500,000 gallons per day.
Table 6 below lists the estimated current rate of with-
drawal of ground water from wells in Southold in average gal-
lons per day for each day of the year.
TABLE 6
ESTI~L~TED 1966 WITHDRAWAL OF WATER IN ~OUTHOLD
Greenport Water System
Private Permanent Homes
Private Sumner Homes
Private Irrigation Systems
Total Withdrawal 1966
Average.For Year
Gallons Per Day
600,000
700~000
200~000
5,500~000
7,000~000
Quality of Water
The quality of the fresh water from wells in Southold
is generally very good, from a chemical and bacteriological
standpoint. However~ chlorides caused by intrusion of sea
water have caused cohtamination in certain areas clo~e to the
shore line and to salt water inlets. The danger of future
contamination caused by salt water intrusion is discussed
in.the next two sections of this report.
The hardness Of the water from wells of the Greenport
System ranges from about 40 to 200 ppm~ or from soft to hard.
In general, ground water in Southold used for domestic pur-
poses and irrigation is moderately hard and is well within the
limits of concentration of iron, manganese, chloride~ sulfate,
and total solids prescribed by the U. S. Public Health Service
for interstate carriers. Except where chloride content has
increased because of salt water intrusion~ chlorides in Southold
wells generally range from 10 to 50 ppm, as compared to the
250 ppm limit gen'erally considered the maximum concentration
permissible for potable water.
Southold's ground-water supply generally.is cool~ clear,
and pleasing to the taste. Unlike certain areas of Long
Island~ where there has been extensive residential development
prior to sewer constructions'there have been no serious prob-
lems caused by detergents in the well water. Greenport has
a sewerage system~ consisting of a primary plant.with effluent
discharging into Long Island Sound. Other areas should be
se~ered at locations where there is a concentration of
residential development and water is draw~ from individual
shallow wells.
22
IV. GEOLOGY
Subsurface Conditions
Most of the wells in Southold terminate at comparatively
shallow depths in upper Pleistocene deposits which are the
source'of the fresh water used in Southold. Three deeper
wells have been extended through older formations in-Southold.~
one in Orient Park (S189), one in Greenport (S491), and one
at Nassau Point (S3123). The first two extended to bed rock
and the third extended into the Magothy formation. Inform-
ation obtained from these three wells, and also from other deep
wells in the eastern part of Long Island, indicates that it
is probable that the water contained in the older and deeper
formations is too high in chlorides for domestic use and that
no substantial quantities of fresh water for use in Southold
may be obtained from these older formations.
Bed rock in Southold is from about 1,000 feet below the
surface in the western part to about 500 feet in the eastern
part. Above the bed rock is the Raritan formation containing
the Loyd sand member, the clay member, and post-Raritan de-
posits which are of the Cretaceous age. Above the Cretaceous
deposits are unconformed layers of Gardiner's clay and the
upper Pleistocene deposits of varied depth, which consist of
stratified and unstratified sand~ gravel, and gravel with
some clay. Most of the ground-water used in Southold is with-
AREA
A
MALCOLM PIRNIE ENGINEERS
WHITE PLAINS~ N.~: - PARAMUS~ N.~.
S6558
Gt~EA T PECONI C BAY
IATTITUCK
S6542
~ CUTCHOGUE
SUFFOLK
LONG
AREA
ISL A ND
B
SOUND
S6524
LITTLE /~ECON/C
BAY
AREA C
s 6 93
GREENPORT
EAST
MARION
~r~
90UTHOLD'
L
THE PREPARATION OF THIE EXHIBIT WAG FINANCIALLY AIDED
THROUGH A FEDERAL GRANT FROM THE DEP~RTMENT OF HOUSING
AND URBAN DEVELOPMENT~ UNDER THE PLANNING ASSIST-
ANCE PROGRAM FOR THE BUREAU OF COMMUNITY PLANNIN~
NEW YORK STATE OFFICE OF PLANNING COORDINATION.
IT WAS FINANCED iN PART BY THE STAT. E OF NEW YORK
GARDItVER'S BAY
AREA
D
FIGURE
ORIENT
St6787
TOWN OF SOUTHOLD
SHOWN ARE WATER TABLE CONTOURS, dULY 1959
( ONE FOOT INTERVAL AND DATUM MEAN SEA LEVEL)
REFERENCE U.S.G.S. WATER SUPPLY PAPER 1619-S$, PLATE
I000 BO0 0 I000 2000
· BASE MAP BY RAYMOND & MAY ASSOCIATES
drawn from these deposits, which generally
sand and gravel. Physical characteristics
are shown in Table 4 of Water Supply Paper
consist of coarse
of this material
1619-GG by mechan-
ical analyses of samples from 28 wells in various areas of
Southold. More recen~ deposits, found along the shores
and marshy areas, include beach and dune sand and gravel, in
some areas mixed with clay.
More complete discussions of the geology of Southold are
given in U.S.O.S. Water Supply Paper 1619-~G, the Bulletin
0W-liS of the New York State Water Resources Commission, and
the numerous references on the geology of Southold contained
in those two reports.
The current comprehensive Nassau-Suffolk water resources
study with its deep well program should provide much valuable
information on subsurface geological conditions in eastern
Suffolk County. It should shed much light on the question of
availability of fresh water from deep wells in Southold and
on the lower limits of fresh water in the upper permeable
glacial deposits.
Surfac~ Conditions
The almost continuous strip of high ground along the
Long Island shoreline of Southold is comprised of till over-
lying sand and gravel. The surface material in most of
Southold is sand and gravel outwash covered by one to three
feet of top soil, consisting of loam of various degrees of
por6sity. These areas are generally excellent croplands.
Surface clay of various depths exist in some areas. This is
true of a sizable area along Moores Drain. This stream dis-
charges a comparatively large quantity of fresh water into a
salt water bay sou6hwest of Greenport at times of heavy rain-
fall. Sand and gravel shore deposits exist along the north
and south shore line of Southold. Orient Point Park consists
of a long'narrow sand spit between Long Beach Bay and Gardiners
Bay.
Plate 1 of U.S.G.S. Water Supply Paper 1619-GG is a sur-
ficial geological map of the Town of Southold. It is repro-
duced and included herein as Plate B in the back of this report.
The top soil in the uplands or croplands of Southold varies
in permeability, as indicated by permeability tests of samples
of loam taken at depths of from one-half foot to two feet below
the surface. The surface soils range from sandy to silt loam,
locally known as sassafras sandy loam, sassafras loam, and
sassafras silt. It is suitable for production of large yields of
vegetable crops when water is applied by spray irrigation during
dry periods. The character of the soil and the gently sloping
topography permit advantageous use of mechanical equipment for
planting, cultivating, and harvesting crops.
V. HYDROLOGY
Recharge of Ground-Water
The only source of replenishment of the underground fresh
water supply of Southold is the rain which falls on the land.
The sandy loam top soil and the underlying sand and gravel
permit much of the rain to enter the ground. The gently sloping
terrain and large areas of cultivated lands retard overland
flows, as indicated by observations of run-off and stream flow
during periods of heavy precipitation. It is estimated that
the amount of rainfall that discharges overland to salt water
each year averages about 15 per cent and may be as low as 10
per cent in extremely dry periods.
A relatively large portion of rainfall returns to the
atmosphere through evaporation from the soil and through the
transpiration processes of natural vegetation and crops. These
losses vary with distribution of rainfall, atmospheric condi-
tfons, and temperatures. It is estimated that they range from
40 to 60 per cent of rainfall and average about 50 per cent.
Assuming 10 per cent of rainfall is lost through run-off
and 50 per cent through evaporation and transpiration, the re-
maining 40 per cent is available for recharge. The estimated
annual recharge ~n this basis is about 18 inches in the western
part of Southold during a year'of average rainfall, and was
about 12.8 inches during the record 3-year dry period 1963,
1964, and 1965.
The total area of Southold is about 43 square miles. Re-
ducing this to 40 square miles because of pavement and clay
~7
areas~ the computed annual average recharge in western Southold
is about 12~500 million gallons in a year of average rainfall
and about 8~900 million gallons in the three dry years of record.
The recharge probably would average about ten per cent less in
the eastern part of the peninsula~ where rainfall records indi-
cate that average precipitation is somewhat less than in the
western part.
Storage of Underground Water
Information obtained to date from records of well drilling
operations in Southold indicates that the available fresh water
supply is stored in the sands and gravels of the upper Pleistocene
glacial deposits, which are 200 feet or more in thickness. These
deposits contain fresh water and also salt water. Because of
its lesser specific gravity~ the fresh water floats or rests
on the heavier salt water. The surface of the fresh ~ater slopes
from a few feet above a mean sea level in the central pa~t of
each of the areas A, B~ C~ and D to sea level at the Sound~ bays~
and salt water inlets. The elevation of fresh water varies each
year in accordance with rates of recharge and withdrawal of
water by pmnping. Also~ a considerable amount of ground-water
gradually seeps laterally through the porous underground material
into the surrounding bodies of salt water.
Much information is available as to ground-water levels
in Southold from 194~ to date. Wells in Long Island are number-
ed in accordance with a system established by the New York State
28
Water Resources Co~nission. Records of ground-water levels,
as measured by static levels of water in wells throughout Long
Island, are maintained at the office of the U. S. Geological
Survey i~ Mineola. Plate 1 of New York State Water Resources
Bulletin GW-45 shows by contours ground-water elevations in
Southold in April 1950. Plate 3 of Water Supply Paper 1619-GG
is a similar map of Southold, showing by contours levels of the
water table in July 1959. This plate is-reproduced and included
as Plate C at the end of this report. It shows the locations of
wells in Southold by numbers. Measurement of static wate~ levels
in these wells provide the water surface data from which the con-
tours were established. As shown on Plate 1 of Bulletin GW-~5
and Plate 3 of WS Paper 1619-GG, the water table throughout
Southold was considerably lower in April 1950 than in July 1959.
This was caused by the fact that withdrawals for irrigation
were greater and rainfall was somewhat less in the two to three
year period that preceeded the July 1950 series of measurements.
The limits of Areas A, B, C, and D, and Little Hog Neck and
Great Hog Neck are shown on Plates A and C. For convenience,
these limits and the underground water level contours in July
1959, taken from Plate 3'U.S.G.S. Water Supply Paper 1619-GG,
are shown on Figure 4~ a reduction of the base planning map.
The highest ground-water levels are in Areas A and B in the
western part of Southold~ and gr0und~water levels in Areas C and
D and in Little Hog Neck and Great Hog Neck are generally loweri
As'shown on Plate C~ high ground-water levels inJuly 1959 were
7 to 8 feet above mean low tide in Areas A and B, and. o~ly --
2 to 3 feet above the mean sea level in Areas C and D and
29
1 foot above sea level in Little Hog Neck and Great Hog Neck.
The quantity of fresh water stored underground in each
of the six island-like areas mentioned above depends on the
vol~ne and permeability.of the materials which stere'the water.
The lateral limits of each are shown on Plate C.
There is sufficient information on static water levels to
establish upper limits of the fresh water. However~ only a
few wells in Southold are deep enough to establish the division
or interface between fresh and salt water. Because of the
general uniformity of the underlying sands and gravels, it is
probable that the division between fresh and salt water conforms
to the Ghyb~n-Herzberg principle or formula, This formula is
in the form of the following equation~ in which h = depth of
fresh water below sea level; t = height of fresh water above
sea level; and g = specific gravity of sea water as compared to
a specific gravity of 1 used for fresh water:
h = t
g-1
Using a specific gravity of 1.025 for sea water, the equation
indicates that fresh water will extend 40 feet below sea level
for each foot that it extends above sea level. This formula
provides a reasonable method for determining the approximate
division between fresh and salt water when both waters are stored
in an unconfined fairly uniform material.
Figure 3 is an idealized section of an island or peninsula]
sho~ing the relationship of fresh water and salt water. Similar
FIGURE NO. :3
SEA LEV~ND 'SURFACE
· .., ¥-~... . '~.~.'?.*~;~.~
'?.'.::*'.':!i.:i. .~.: .".:..'.'.'?**'~
-.-...,:,., SA.D A.O GRAVEL .-.,'
~- ..~',' ~.:,~: -^~.- CONTAIN I N G '~'~ ~.' '~
. ",'. · :~',*' 7'* ' ~..'.- ' '-'.'.',
~. ~..,....{,.:~ ./..~. '&.~ . . ..._,,,:~;M'..
~ ).,.,** *,, h FRESH WATER ~.'.'.".~:~ .,.;..,,.,,.
.~ ~:.*";'--'~.'~"" ~,:""' ~'& 'F"~' '&' '.~;~"~'&
· ~ '_~.*;'*'. ;^' .'"*.V'a* .':,.'f .~*~ .*.. '3;.
:~'~-..~..~:.'..'.~.?.'..v.4~ °~.".~.'~.;. ',~:a.'<.~'.
. ~ ~:.~: . ~' ~ .'~ ~" .'5. .% .~" 't" ~. ' Y',: '~'. ~.~. ".~ ~a ~ '*''. .~' u. '~.~'..~ ~ ~. : "v. .~'.~. .~'.,'~. ~ 3 '~'."f..'~' . ' ~. "~
?~'~.'¥:~; ~.'~ ~:~.+.9.,~:.~.'~,'.",'.v'.j..:v:.~.,/.".4:v'e'.~.'.v:~.'.~'.v..~.~.~'~.:e~ 'v:[~;~ '~..~' v.~:.~.~ .~...~.. ,'.~,*
~'..^. · ~,.'~.... ~: .<. :.v'.~ ~ '~ '.~ ..~
~,,.'?.-~.~'-.~ SAND AND GRAVEL CONTAINING SALT WATER ,'z.~'.~"."~'-'~:
~::,. *:~.'^' :,~. '.¢"*~':':?,::;,:,,,.'.":'.".'::?:-.¥~'. ¥ *.;':v'?.~ .,.~;.* :~.:':~:~..' .;?. ¥'-..' ~.;~.~ .~,'~ *:.~'~.."-'~.^"..~?.~
,: ~ =.'...:~...v: :..?.'.~...::.'.v...~ :.:-:~. : . :~.~v'. ~,.~,'../,..~.~.~.?~. :.' .:.~.;,:?. :,.. ~.~...~ :~.~: ...,.;.:.:/: ~. .'~ ,.-: : .,..? ~/.~...: ...,. ~'...? ;v..,
~..~.~-.~..~ ,...~.,. :<*:.., ~:.~..+,~..~ .,...,..,..,~* ~,. ^ ~.~...~ .~:~-.*.~. ~ ,~ .,~: .~ ~.,:,~ ..~: ~-...,'. ~ '.,.:.,.~. ~ .~.:.'..~.~?.. =...~.~,...
· "~" '.~."<"~'.'"~.~;..'^'~:~' '<.'.~. ': '" · 'Tr:~' ','/ ' .' '4 ~.' '~,':'~.": '~,:"4.~::k "+.~.'~.-/.'a. · .~.~.-..,~.~"<." ·
· -~' I~'~'.~. * ~..--~-Y...~.,~.,d '' ~.'~e:~' ~ e~"k' "Y.'~'~'. .... .e.v'l.:T-' :~..~x.~.. ~"~'v.'~.'~'¥'- v"~*
TYPICAL GEOHYDROLOGIC SECTION
SHOWING RELATION OF FRESH AND SALT WATER
( ACCORDING TO THE GH.YBEN- HERZBERG PRINCIPLE )
MALCOLM PIRNIE ENGINEERS
WHITE PLAINS~ Nfl.- PARAMUS~ N.J.
section, s are ~nclu~ed in a number of hydrological studies to
illustrate application of the Ghyben-Herzberg principle.
As an aid in estimating tt~e approximate quantity of water
stored in each of the six hydrological sections~ Plate 3 was
included in Water Supply Paper 1619-00.
Plate D of this report.) It shows, by a
and five transverse sections~ the upper~
(It is reproduced as
longitudinal section
lateral, and lower
limits of the underground fresh water reservoir. The inter-
faces or zones of' diffusion between fresh water and salt
water were obtained by applying the Ghyben-Herzberg principle
to the water table elevations in July 1959, as shown by the
~ections on Plate D.
In WS Paper 1619-GG~ Crandell computed the volume of the
fresh water aquifer in each area~ and applied a specific
yield of 22 per cent to obtain an estimated total volume of
fresh water in storage. Table 7~ which follows~ shows his
estimated volume of fresh ground-water in storage in:July
1959.
Although these estir~tes can be considered only as
approximations~ they are based on reasonable assumptions as to
underground conditions. They indicate that over 90 per cent
of the fresh water storage at Southold is in Areas A and B and
that less than lO per cent is in Areas C and D, Little hog
Neck and Great Hog Neck.
31
TABLE
Estimated Volume Estimated Volume
of Deposits Satu- of Fresh Water
rated with Fresh in. Storage
Water
Area ( Mill. cu. ft. ) .( Mill. Gallons )
A 28,200 46,000
B 82,000 134,000
C 6,400 10,400
D 6~ 400 10,400
Little Hog Neck 600 1,000
Great Hog Neck 2,900 4,700
12--~6-~ 500 20--6-g, 500
Note: Figures in Table 7 are taken from WS Paper 1619-GG,
pp GG-23 and GG-24
Variations in Ground-Water Levels
Figures 5, 6, and 7 show variations in ground-water
levels in certain wells in Areas A and B from 1949 to 1966,
inclusive, and in certain wells in Areas C and D from 19~9 to
1966, inclusive. The low ground-water levels in 19~9 and
1950 were caused by excessive withdrawal for irrigation
purposes. The very low'ground-water levels in 1966 resulted
from record low rainfall from 1963 through 1965. Deficient
rainfall also caused comparatively low ground-water levels
in 1957.
.-~
3.0
l--
hi
-- 2.0
--I
I. 6.0
4.0
7.0
6.0
5.0
4.0
2.0
1.0
1949
1950
,~ ~ ~
1951
~ = .~
1952
1953
FIGURE
1954 1955 1958 1960 1961 1965 1964 1965 1966 1967
1968
NO. 5
7.0
6,0
5.0
4.0
$.0
2.0
6.0
5.0
4,0
2.0
1.0
9.o FIGURE NO. 6
9.O
8.0
7.0
Z
-- 4.0
Z
~ 4.0
3.0
2.0
1.0
0
8.0
7.0
6.0
5.0
4.0
2.0
4.0
3.0
2.0
1.0
0
1949 1950 1951 1952 J953 1955 1961 1962 1963 1964 1965 1967 1968
FIGURE NO.7
,5.0 5.0
4.0
~J
bJ 2:.0
.-I
0
~958
1959
1960
1961
i962
1963
1964
1967
4..0
3.0
2.0
1.0
0
5.0
,4.0
$.0
2.0
32
VI. AVAILABILITY OF FRESH WATER
Salt Water Intrusion
The danger of salt water intrusion is the principal
limiting factor in the amount of water that can be safely
withdrawn from the ground in various parts of Southold. This
is because the fresh water in storage is Surrounded on all
sides and beiow by salt water, as shown on Plates C and D. The
danger of ~alt water intrusion is more serious at locations
where the static level of the fresh water is only a little
above mean sea level. This is particularly true in Areas C
and D, Little Hog Neck and Great Hog Neck, and areas adjacent
to bodies of salt water in the other parts of Southold. With-
drawals of water from these areas for domestic use and irri-
gation can not be increased to any appreciable extent without
causing contamination of the supply by either lateral or verti-
cal intrusion of salt water.
A number of instances of salt water contamination in
Southold are recorded in Water Supply Paper 1619-GG and other
reports. In some instances, the contamination has been caused
by lateral movement of salt water into the fresh water where
the wells were located close to bodies of salt water. Excess
chlorides caused by vertical movement of the salt water has been
experienced in the past, particularly during periods of low
rainfall~ in water withdrawn from wells used for irrigation
and water supply.
33
Estimated Safe Yield
A number of factors affect the quantity of fresh water
that may be safely withdrawn from the ground in various parts
of Southold. The principal factors are amount and distribution
of rainfall~ character~of surface and underground materials~
purpose for which the land is used, location of points of with-
drawal in reference to salt water, and the elevation-of and
variations in ground-water levels in the general vicinity of
the points of withdrawal.
Records of rainfall~ ground-water levels, and underground
conditions in Southold developed during wet and dry period~
for the past 15 to 20 year period generally are available. To
a lesser.degree, records of the. quantity and chloride content
of water withdrawn in various parts of the Town are availab, le
and are helpful in considerations as to the safe yield of under-
ground water during periods of low rainfall.
Based on a study of the records and experience on with-
drawal of water during the past 15 or 20 year period,'it is
estimated that the approximate yield of Southold's ground-water
supply is approximateiy 40 per cent of recharge during periods
of three consecutive years. In Section V of this report, it
was stated that estimated annual recharge during periods
average rainfall is about 12~500 million gallons and is about
8~900 million during extremely dry periods, such as those ex-
perienced recently. Using 40 per'cent of recharge for yield,
the estimated yield in a period of average rainfall would be
5,000 million gallons, or an average of 14 million gallons
per day, and during a three-year period of minimum rainfall,
the yield would be about B~600 million gallons, or an average
of lO million gallons. For purposes of this study, an average,
of l0 million gallons per day will be considered as the safe
or dry weather yield of the underground water supply of Southold.
At present, an average of about 7 million gallons of fresh
water per day are withdrawn for domestic and irrigati0nal uses.
In accordance with the above estimates of available y~eld, an
additional withdrawal of about l0 million gallons per day
could be made during years of average rainfall. However, the
safe yield of a water system must be based on years of record
low rainfall.
This indicates that withdrawals of l0 million gallons, or
~ million gallons in excess of 1966 withdrawals, may be safely
made in the future under conditions of withdrawal designed to
prevent salt water intrusion ....
Relationship of Available Ground-Water to Plannin~
As shown in Table 6 of Section III, total estimated with-
drawal of ground-wate~ was an average of 7 million gallons per
day for &ach day during the year o~ which an average of 5.5
million gallons per day. was used for irrigating vegetable crops.
Assuming that the number of acres .irrigated and irrigation practices
35
will remain about the same as in 1966, the safe yield estimate
of 10 million gallons per day in dry weather indicates that
about 3 million gallons per day will be available for domestic
~se.
It is estimated that future average per capita water use
in Southold will be about 120 gallons per day for permanent
residents and about 80 gallons per capita per day for an average.
of two months per year for summer residents. This is equivalent
to 16 gallons per capita per day for each day of the year. The
120 gallon per day allowance for permanent residents is higher
than present use and ,is based on the assumption that domestic,
'commercial~ and light industrial, use will increase in the future.
It is probable that the number of seasonal residents will
increase in the future, as Suffolk County developments extend in
an easterly direction. Assuming that summer residents increase
three-fold to abbut 45~000 persons within the'next 20-year period:
this will mean additional water consumption of about 500~000
gallons for each day in the year. This will ~eave about 2.5
million gallons for an increase in permanent residential use.
Assuming a per capita consumption of 120 gallons per day,
the remaining 2.5 million gallons will provide for more than
20,000 persons, or a total of 36,000 permanent residents, in
addition to 45,000 seasonal residents. As stated above, these
estimates assume that the amount of water used for irrigation
will be equivalent to 5-5 million gallons per day for 365 days
a year.
Irrigation water use of 200,000 gallons per acre per year
is equivalent to'the consumption of about 5 permanent residents,
or more than 30 summer residents.
If withdrawal of water for irrigat&on'is decreased in the
future, the safe yield will provide a supply for a greater
number of additional permanent and/or summer residents than
indicated in the previous paragraphs.
.Conversion of Salt Water
Considerable pzogress has been made during recent years
in research, and in pilot plant and plant scale operations
related to conversion of salt and brackish water to fresh
water. However, costs of construction and operation of saline
water conversion plants are generally prohibitively high,
except where an adequate supply of fresh water is unavailable.
Several operating plants of 3 million gallons and less
per day are tin operation or are in the planning or construction
s6age of development. These include
in the Virgin Islands, Saudi Arabia,
Naval Base at Guantanamo Bay~ Cuba.
operating plants lodated
North Carolina, and t e
However, the cist of con-
struction, maintenance.~ and operation of these plants is very
high. Lower costs are estimated for large plants which will
combine power production with salt water conversion by utili-
zation of atomic energy. F~nancial arrangements of a large
plant of this type at Long Beach] California, recently have
been completed. This plant is being designed to produce
150 million gallons of fresh water per day, as well as large
quantities of power for use in the Los Angeles area. Condl-
tions at that location are comparatively favorable for a
large atomic power and saline conversion plant.
The New York State Atomic and Space Development Authority
has been developing plans for a combined atomic powered elec-
trical generating and saline water plant at Surfside in the
Town of Riverhead. The initial water plant will have a
capacity of about one million gallons per day, with provision
for future increases in capacity. Preliminary plans for this
installation have been in progress for some time. At present
the plant is being'designed, and operation is scheduled for
1970. An agreement has been made with the Town of Riverhead
to purchase one million gallons of fresh water a day at an
initial cost of 35 cents per t000 gallons, with a provision
for a gradual increase to 45 cents per 1000 gallons in the
first 10-year period. The plant will be located on Long
Island Sound, relatively close to the border line of the'
Towns of Riverhead and Southold. The capacity of the Power
Plant will be 2500 kilowatts. The Long Island Lighting
Company has agreed to purchase electric power from the install-
ation at a cost of 15 mills per kilowatt hour.
There is more than sufficient ground-water available in
the western portion of Southold for present and probable
future needs, unless an unforseen industrial demand for fresh
water develops.
It does not appear to be economically feasible
for Southold to utilize converted sea water from this plant
for domestic, commercial~ and irrigation use in the foreseeable
future.. However, if industries which use a large quantity of
fresh water are developed in the western part o£ Southold,
they may find it advantageous to obtain water from the
proposed Surfside Plant.
VII. PROTECTION OF GROUND-WATER RESOURCES
It is essential that Southold employ every available means
to protect its limited ground-water supply. Following are
me~hods
1.
2.
4.
that should be investigated and considered:
Control of future water withdrawals.
Location and spacing of wells.
Extension of public water facilities.
Discontinue approval of projec£s which include
dredging channels inland from salt water estuaries
or bays.
Construction of dikes across drainage channels
near shorelines.
Recharge of '~quifer with surface waters.
Control of Future Withdrawals
At present the installation of wells for public water
supply and commercial and industrial use is subject to the
approval of the State Water Resources Commission. State
regulations also require filing of data for record purposes
on wells other than small wells serving individual homes or
buildings. However, th~ state do~s not exercise control over
installations and the amounts of water that may be withdrawn
from irri~ation wells.
The location, spacing, and amount of water withdrawn
from large wells are important factors in the protection of
the fresh water supply in Southold from salt water intrusion.
The advisability of the Town exercising control over future
well installations from a legal, engineering and administrative
standpoint should be given serious consideration.
'Location and Spacing of Wells
The location, spacing· and depth of wells of large capa-
city depend upon a number of factors· and each new installation
should be considered individually. Such wells should be
constructed at some distance from salt water and at locations
where minimum static ground-water levels are two feet or more
above mean sea level. In general, they should be spaced at
least 500 feet apart and about 1000 feet from the shore of
salt water bays or inlets. Samples of water should be taken
and tested for chlorides· particularly at times of low ground-
water levels and heavy withdrawals. Pumping should be dis-
continued whenever a definite increase in chlorides is indicated.
Wells to provide large'quantities of water for public water
supply should be constructed in the ceutral portions of ~eas
A and B · where ground-water levels are comp~ratlvely high.
Extension of Public Water Supply Facilities
The Greenport Wate'r System supplies water to about one
third of the total permanent population of Southold. Most of
the remaining permanent and summer residents are supplied by
shallow individual wells. The water'from many of the wells
that are close to salt water is of poor quality. In areas
where homes are not very far apart· there is always the danger
of pollution. Also, excess removal of fresh water from the
ground-water table near the shore eliminates the existing
natural fresh water barrier.
As the population becomes more dense in many areas of
Southold, public water supply facilities should be provided.
The Greenport Water System should be gradually extended east-
ward along Main Road to supply water to the unincorporated
villages of Orient and Orient Point. The East Marion Wells
and a new well near Main Road north of Orient village could
be used to advantage to supply the comparatively small water
consumption in this part of Southold , which has been designated
Area D.
Certain areas adjacent to the Main and North Roads, and
along the southerly shore line of Southold, between the pre-
sent limits of the Greenport.Water System and Mattituck,
including built-up areas of New Suffolk and Mattituck, should
have public Water service with adequate fire protection facili-
ties in the near future.
This service could be supplied best by extension of the
Greenport System or by a new system developed and operated by
the Suffolk County Water Authority. Both organizations are
experienced and competent to provide efficient service. Decrease
in insurance costs and increase in property values resulting
from an adequate water system will compensate to a considerable
extent £or the cost of the service.
Inland Salt Water Channels
In recent years, approval has been given to extending
inland from salt water bays or estuaries certain dredged
channels to provide for development of marinas or water re-
sidential property. As shown on Plates A and B, in the vi-
cinity of each natural or dredged channel extending inland,
the contours representing very low ground-water levels extend
for a considerable distance from the shoreline of the estuary.
This provides a shorter distance of travel, and thereby in-
creases the loss of fresh water from storage and the possibility
of salt water intrusion into nearby well supplies. Recently,
applications for approvaI of such projects have been made.
There are many sites aloug the water front of Southold
where such developments can be made at low cost. Many future
applications for approval of construction of inland salt water
channels can be expected unless approvals for such developments
are denied by the Town. ~umerous coves and bays along the
South Shore provide sites suitable for marinas and water fronb
residential properties, and it is not necessary to endanger
the underground water supply by the extension of salt water
channels inland.
Drainage Channel Dikes
The surface contours on the Geological Survey maps of
Southold and field observations indicate that there are a
number of drainage channels that extend to the south shore
line of Southold~ across which it may be feasible to provide
low dams or dikes to restrict surface and underground
drainage of fresh water into salt water inlets or bays. In
some instances it might be advisable to construct excavated
ponds above the dikes to store fresh water at elevations above
mean tide level. Available information indicates that many of
the drainage basins are covered by marsh deposits i'which Would
tend to store the fresh water above sea level. Some of the
dikes would serve to convert existing salt water inlets into
fresh water ponds.
It probably would be advisable to provide sheet pile
cut-offs under some of the dikes. Inlet and outlet facilities
in the dikes will be necessary to control the water above and
below each dike. Each installation would provide a water
'barrier which would retard fresh water underflow from the
ground-waker storage basins to the sea. The locations which
offer the most promising possibilities for this type of
installation are numbered 1 to 16, inclusive, on Plate A.
Surveys and borings are necessary at each location to establish
the feasibility, effectiveness, and cost.
Recharge of Surface Waters
The State Highway Department and some of the Counties
and Towns in Long Island have designed highways and, in some
instances, storm drainage systems to discharge into excavated
recharge basins extending into the coarse sand and gravel
material. Some have been constructed in Southold. This
practice should be continued.
For a number of months each year, the Village of Green-
port pumps water from a pond located on Moores Drain and dis-
charges it on lands a. round wells in Well Fields Nos. 2 and 3.
The water level in the wells is raised and an increase in
the yield results. Much of the surface of the drainage area
of Moores Drain is comparatively impervious, and during periods
of heavy rainfall large amounts of fresh water are discharged
into Pipes Cove. Additional storage ponds for recharge should
be constructed on Moores Drain.
The sewage of Greenport is now treated in a primary plant
and the effluent is discharged through a subaqueous outfall
extending into Long Island Sound. Extensive experimental
methods for complete treatment of the effluent from its
activated sludge treatment plant and discharge of the effluent
into the ground to form a fresh water varrier are being con-
ducted in Nassau County by the County and the U. S. Geological
Survey. This program includes the construction of a complex
'recharge well and nearby test wells to permit a series of tests
on the effect of th~ recharge of the treated wastes on the
water-bearing sands at various depths. It is expected that
this program will provide considerable data relative to the
feasibility of treating large quantities.of liquid wastes to
· such a degree that they can be returned to the ground and in-
crease the available underground fresh water supply under
conditions such as those prevailing in Long Island. Similar
treatment and recharge of ground-water aquifer have been'
undertaken in California and other states.
At present it is not necessary nor economically feasible
for Greenport to change its method of disposal of sewage.
However, the aforementioned method should
for disposal of sewage from Greenport and
areas of Suffolk County in the future.
be given consideration
other thickly settled
VIII. Fishers Island Water Resources
General Conditions
Fishers Island is in Long Island Sound, about 11 miles
northeast from Orient Point and ? miles southeast from New
London. It is about 6 miles long and about one-half to a
mile in width, and its area is 4.2 square, miles. The inset
on the right hand portion of Plate A shows the main features
of the Island including roads, ponds and the location of the
water supply mains.
Fishers Island has long been famous as an attractive
summer resort. Its rolling hills, irregular shoreline and
large areas of natural woodlands provide exceptionally beau-
tiful scenery.
Most of the easterly portion of the Island is owned by
The Fishers Island Club and its members. In this section
there are a number of summer estates that were established
many years ago, and also extensive areas of undeveloped fields
and woodlands.
A large part of the westerly half of the Island is owned
or controlled by Fishers Island Farms, Inc. Many people spend
all or part of the summer in this part of Fishers Island. ~ '
Portions 6f the western part of the'Island have b~en used'from
time to time
deactivated.
A ferry
Many persons use privately owned boats and planes
for military e~tablishments, but these hav~ been
from New London provides access to the Island.
to reach
the Island.
The climate is about the same as in other parts of Southold.
However, the topography and underground conditions are different.
There are hills up to about 160 feet high in both'easterly and
westerly portions of the Island. Much of the land is undevel-
oped and generally is less pervious than the mainland areas
of Southold, and a much larger portion of the rain drains
overland to fresh water ponds and to the surrounding coves
and bays. Glacial deposits occur in some areas and these are
possible sources of fresh water, but the water from wells in
these deposits generally is high in iron and in some cases it
is high in chlorides.
~opulation and Water Consumption ·
The permanent population of Fishers Island varies between
400 and 500 persons. It is estimated that maximum peak popu-
lation during summer weekend periods is about 5,000 persons.
The Fishers Island Estates Corporation owns the wate~
system which supplies water on a retail basis to the eastern
part of the Island and, on a wholesale basis, to Fishers Island
Farms, Inc., which owns and operates the distribution system
in the western part of the Island. As indicated on Plate A,
these two systems provide water service to most of the developed
areas throughout the'Island.
The following tabulation lists the amount of water pumped
from the treatment plant each month in 1965 and in 1966, expressed
in terms of 1,000 gallons per month.
48
Table 8
WATER PUMPED FROM THE FISHERS ISLAND TREATMENT PLANT
(1:000 GALLONS PER.MONTH)
1965 1966
January 2,366 2,288.
February 2,384 2,272
March 1,772 2,266
April 2,244 3,037'
May 6,401 4,033
June 10,087 7,589
July 14,419 14,123
August 11,770 12,060
September 7,185 '6,215
October 3,665 4,279
November 2,708 2,882
December 2,420 4,780
Total
Ay. Da%ly- 186 170
Ay. Day
Max. Month 465 458
Av. Day -
Min. Month 57 73
As shown in Table 8, average daily pumpage in 1965 was
186~000 gallons per day. During July, the' month of maximum
consumption, it was 465,000 gallons per day. Maximum daily
use occurred on July 14, 1965, when pumpage of 628,000 gallons
was recorded.
There is no indication that there will be a substantial
increase or decrease in water consumption during the next l0
or 20 year period.
49
Existin~ Water System
The main source of water supply is from two shallow fresh
water Ponds, Barlow Pond and Middle Farms Pond. Normally,
both Ponds provide gravity flow to the suction of low lift
pumps which raise the water for treatment to a filtration
plant that has a nominal capacity of one million gallons per
day. The 1963-66 extremely dry period depleted the available
storage in the two Ponds to an alarming degree, and a 6-inch
test well and an 8-inch gravel packed well wSth 12-inch outer
casing were installed near Middle Farms Pond in the summer of
1966. Water was discharged from this well into the Pond
during the latter part of 1966. Initial tests of the well
water indicated that it contained more than desirable quantities
of iron. Possibly the water quality will improve with use.
The use of these wells was discontinued early in 1967 when the
Ponds were filled by surface rhnoff resulting from normal
rainfall.
The water treatment plant is located near Barlow Pond. It
is a well designed and operated'~lant with a nominal capacity
of i million gallons. ~This plant is adequate for ~resent and
probable future use. The high lift pumps are rated at 800
gallons per minute. The clear water storage basin at the
plant has a capacity of 400,000 gallons.
50
It is feasible to add storage to the surface supply system
by utilizing'Treasure Pond, A portion of a larger pond, Island
Pond, could be utilized for storage.by providing dikes to main-
tain the northerly portions of the Pond as a fresh water Pond.
This Pond became salted during a hurricane storm and the lower
portion is now used to produce seed oysters.
The new well and test well, which have a combined installed
pumping capacity of 250 gallons per minute, are available for
supplementing the surface supply, if this is necessary. The
two new wells provide means for increasing raw water supply
when mixed with stored surface water. Additional pumping and
testing should be carried out p~riodically to determine whether
iron content has been reduced to satisfactory limits. Should
unexpected increase in demand occur, iron removal and chlorination
facilities could be added to permit regular use of the well
water.
The distribution system consists of a principal 10-~nch
feeder main extending easterly and westerly from the treatment
plant, and smaller branch mains. A million gallon capacity
stor'age reservoir, located on Chocomount Hill about 1-~ miles
east of the treatment plant, floats on the system and controls
the static pressure. A 500,000 gallon storage reservoir,
known as the Bell Hill Reservoir, originally provided stbrag~
on the westerly part of the sys6em. This is an uncovered
reservoir and it is understood that it has not been used for
many years by order of the State Health Department.
51
There are approximately 80 hydrants in the system. Hydrant
tests made by the New York Fire'Insurance Rating Organization
a few years ago indicated that only a few hydrants could deliver
500 gallons per minute and many of them could not deliver 250
gallons per minute at 20 pounds per square inch residual pressure.
A detailed investigation of the adequacy of the distribution
system is beyond the scope of this report. However, it Is
apparent that the system is inadequate to provide sufficient
water to many of the existing hydrant~ in both easterly and
westerly parts of the Island. A competent water works consul-
tant should be engaged to make a detailed investigation'and
report on the need for additional distribution storage and/or~
mains and the ~ecommended improvements should b~ undertaken 4
as soon as possible tO provide sufficient water at hydrants ~
for adequate fire protection.
General
52
IX. CONCLUSIONS AND RECOMMENDATIONS
Southold has no surface streams or lakes of appreciable
size, and its sole source of fresh water is ground-water stored
in the relatively pervious glacial deposits which exist through-
out most parts of the peninsular portion of the Town. Most of
the wells which withdraw water for public water supply, irrigation,
and individual domestic use are
which extend from a few feet to
deposits.
Estimates of Safe Yieid
Rainfall in Southold averages about
During the record three year dry period
comparatively shallow wells
about 100 feet into the glacial
45 inches a year.
( 1963,. 1964, and 1965)
the average was only about 32 inches, and in 1965 only 26.?
inches were recorded at the Cutchogue Station. A relatively
large portion of the rainfall returns to the atmosphere through
evaporation from the soil and through the transpiration of
natural vegetation and cultivated crops, and about 15 per cent
flows overland to salbwater. It is estimated that 50 per cent
of the rainfall enters the ground and that about 200 million
gallons of fresh water is stored above saltwater during averaMe
periods of rainfall. However,~ onl-y a portion of this can be
withdrawn without causing contamination of the fresh water supply
with saltwater. Some of the stored fresh water flows laterally
to the various bodies of water which almost completely surround
Southold. Furthermore, it is not safe to withdraw fresh water
from any portion of Southold to such an extent that the ground-
water level is below I or 2 feet above mean sea level because
of danger of contamination by saltwater.
As described in Section VI of this report, the danger of
saltwater intrusion is the principal limiting factor in the
amount of fresh water that can be safely withdrawn from the
'ground in various parts of Southold. In this section of the
report, it is stated~that the estimated safe yield is about
6,000 million gallons per year during normal periods of rainfall
and about 3,600 million gallons per year, or an average of about
l0 million gallons per day in an extremely dry period. These
estimates are based on a number of factors, including records
of ground-water elevations, withdrawals for various purposes,
and hydraulic computations based on data obtained from various
sources. Fortunately, there have been extensive past investi-
gations made by representatives of the U. S. Geological Survey
and others on ground-water conditions in Southold which provide
muc~ useful data.
Estimates of Population and Water Use
It is estimated that the present population of Southold
is about 16,000 and that peak population in summer months is
about two times this. figure.
The water System owned and operated by the VillaEe of
Greenport is the only public wate~ system %n Southold. It
supplies more than 600,000 gallons per day of water to about
53
5,000 persons in areas within and adjacent to the Village. It
is estimated that about 10,000 permanent residents of Southoldt~
not supplied by the Greenport system~use an average of about
700,000 gallons per day and that some 15,000,000 summer residents
use about 72 million gallons per year or the equivalent of an
average of 200,000 gallons for each day of the year. The total
estimated withdrawal of water for domestic use now averages
1.5 million gallons per day. Approximately 12,000 acres of
vegetable crops are irrigated during dry periods each year. It
is estimated that average withdrawals for this purposeis about
5.5 million gallons per day, and that total withdrawals average
about ? million gallons per day.
The quality of well water is generally good. It ranges
from soft to hard and at most locations it is moderately hard.
Iron content is greater than desirable in the water from certain
wells. There have been no serious problems caused by detergents,
but this may be a future
these areas?are sewered.
system.
'The above estimates
problem in developed areas, unless
The Village of Greenport has a sewerage
of safe yield and Present withdrawal
indicate that at
addition to present withdrawals,
period of record. Assuming that
for irrigation remains constant,
sufficient water
and about 45,000
least 3 million gallons per day of water, in
are available during the driest
the amount of water withdrawn
the additionai Yield will provide
for a total of about 35,000 permanent resi~entsl
seasonal residents. Average irrigation use is
54a
equivalent to about 200,000 gallons per acre per year, or
about the average consumption of 5 permanent residents or
more than 30 summer residents.
The above estimates indicate
in various parts of Southold must
with sound planning for the most effective utilization
in various points of the Town.
The water resources of Southold are limited to an amount
which does not greatly exceed present use. It is essential that
Southold must employ every available means for protecting this
limited ground-water supply. The following suggested methods
should be investigated and be given consideration:
1. Control of future water withdrawals.
2. Location and spacing of wells.
3. Extension of public water facilities.
4. Discontinue approval of projects which include
dredging channels inland from saltwater estuaries
or bays.
5.Construction of dikes across drainage channels
near shorelines. "·
The
how they
Recharge of aquifer with
need for considering each
should be implemented are
of the report.
that the available ground-water
be considered in connection
of lands
surface waters;
of the above methods and
discussed in Section VII
Possible Supplies other than Ground-Water
The feasibility of utilization of fresh water sources
other than ground-water has been considered. One of these
55
sources is water from the atomic power and saline conversion
plant now being planned by the New York Atomic Space Development
Authority. This plant will be located on Long Island Sound,
at Surfside in Riverhead, not far from northwesterly part of
Southold. This project is described on pages 37 and 38 of the
report. The present contractual cost of water, 35 cents per
1000 gallons at the plant with a gradual increase to 45 Cents,
is far greater than the cost of ground-water. It does not appear
economically feasible for Southold to utilize converted sea
water from this plant in the foreseeable future.
There is an excess of ground-water in portions of the
Town of Riverhead, east and west of the built-up sections. Should
industrial development in the westerly portion of Southold un-
expectedly increase, it may be possible to utilize some of this
excess ground-water.
Fishers Island Water Resources
Fishers Island, an attractive summer resort in Long Island
Sound near the Connecticut and Rhode Island shorelines, is one
of the five islands within the Town of Southold, and it is included
in the study area covered by this report.
It is about 6 miles long; its area is 4.2 square miles;
and the permanent population is about 450 persons, with a peak
of about 5,000 persons during holiday weekend periods.
A privately owned central water supply system extends
throughout
the Island. The principal source of water is surface
water which is drawn from two small relatively shallow ponds
in the central portion of th~ Island. The surfaces of the
Ponds when full are only a few feet above sea level.
Average daily water use is about 200,000 gallons; average
daily use in July, the peak month, is about 4?0,000 gallons;·
and a maximum daily pumpage of 465 gallons was recorded in
July 1965.
The available water in the two presently used storage~
reservoirs was drawn down, in the su~uers of i965 and 1966, to a
degree that caused concern. A test well and larger well were
driven in the summer of 1966 and used to supplement the water
in one of the ponds during the latter part of 1966. Since then,
more than normal rainfall has increased storage,and the use of
the wells has been discontinued. Tests in 196~ indicated that
the well water contained much more iron than is desirable.
Two other ponds are available for additional storage and it
may be feasible to draw down some of the ponds lower than
presently can be accomplished,'without causing saltwater in-
trusion. This can be determined by a testing program of water'in
the ponds. Should the wells continue to produce water high in
iron content, iron removal facilities can be provided at the
wells and, if necessary, they could be regularly used.
The existing treatment plant, which has a nominal capacity
of one million gallons per day, is adequate and well operated.~
The distribution system comprises a main 10-inch feeder
extending easterly and westerly from the treatment plant which
57
is in the central portion of the Island, and a number of smaller
mains. At present, there is only one storage tank in the dis-
tribution system which is located on a hill about 1~ miles
easterly from the treatment plant. A second tank ~s needed in
the westerly part of the Island.
Hydrant flow tests made a few years ago indicate that the
distribution system is inadequate to provide proper quantities
of water for fire protection purposes.
This situation has been confirmed by our present investigations.
It is recommended that competent water supply engineers be re-
tained to make a detailed study of the distr±bution system and
Storage facilities and to recommend needed improvements.