HomeMy WebLinkAboutNF Water Supply Plan 1982NO£T!t FDRK WATER SUPPLY PLAN
SUFFOLK COUNTY, NEW YORK
Dec~mber 1982
Prepared For:
Suffolk County Deparl~ent of Heal th Services
Hauppauge, New York
Prepared By: -'
ERM-Northeast Engineers, P.C.
88 Sun~yside Blvd.
Plainview, New York
Cal~p Dresser & ~Kee
One World Trade Center
Ney! York, N6w York
q
CONTENTS
1.0
EXECUTIVE SUMMARY AND RECOMMENDATI~S ..................... 1-!
1.1 1-1
Executive Summary ....................................
Area Characteristics ................................. 1-1
Groundwater Quantity ................................. 1-2
Groundwater Quality .................................. 1-4
Water Supply Alternatives ............................ 1-5
Implementation ....................................... 1-6
1.2 Recommendations ...................................... 1-7
General Recommendations .............................. 1-7
Area-Specific Recommendations ........................ 1-8
Preventive Measures .................................. 1-11
2.0 INTRODUCTION .............................................. _~-1
2.1 Scope ................................................ 2-I
2.2 StuOy Area ........................................... 2-2
2.3 Planning Approach--Water Supply Zones ................ 2-2
3.0 POPULATION AND LAND USE ................................... 3-1
3.1 Population ...............
3.2 Lan~ Us~...]i .............. ]i ]~]i~ii~]~ii~]i~] ]]~] 3-13_~
4.0 GEOLOGY ...................................................
4.1 Geologic Units .......................................
4.1.1
4.1.2
4.1.3
4.1.4
Bedrock ...................... ~ ................
Raritan Formation .............................
Matawan Group--Magothy
Formation Undifferentiated ....................
Pleistoc6ne Deposits ..........................
4.2 Aquifer Parameters...- ................................
4.3 Fresh Water-Saltwater Interface ......................
4-1
4-1
4-1
4-1
4-1
4-2
4-4
4-5
LIST OF TABLES
]
]
]
]
1
l
)
t
Table 1-1
Table 3-1
Table 3-2
Table 3-3
Table 3-4
Table 4-1
Table 4-2
Table 5-1
Table 5-2
Table 6-1
Table 6-2
Table 6-3
Table 7-1
Table ?-2
Table 7-3
Table 7-4
Table 8-1
Table 8-2
Water Budgets and Consumptive Use Projections ........ 1-3
Population by School District ........................ 3-2
Population by Groundwater Supply Zones ............... 3-3
Peak Summer Weekend Population ....................... 3-4
Existing Land Use .................................... 3-6
Upper Glacial Aquifer Parameters ..................... 4-6
Magothy Aquifer Parameters ........................... 4-7
Percentage of Well Samples Exceeding Standards or
Guidelines for Inorganic Parameters .................. 5-2
Percentage of Well Samples Exceeding Guidelines for
Organic Parameters ................................... 5-7'
Summary of Well Supplies for the Greenport
Municipal System ..................................... 6-3
Summary of Well Supplies for the Riverhead
Water District ............................. j ......... 6-5
North Fork Private Water-Supplie~ .................... 6-7
Existing Water Usage--Greenport and Riverhe~d
Water Districts ......................................
Average Annual Water Usage ........................... 7-4
Irrigation Requirements-for Crops Grown
the North Fork ....................................... 7-~
Summary of Water Budget Analysis ..................... 7-8
Estimated YeaP 2000 Population 'and Water
Water Supply ~oncepts ................................ 8-5
5.0
GROUNDWATER QUALITY ...................................... . 5-i
5 1 Inorganic Parameters ........ 5-I
5 2 Organic Parameters 5-6
6.0 EXISTING WATER SUPPLY SYSTEMS ......................... . ... 6-1
7.0
6 I Greenport Municipal System 6-I
6 2 Riverhead Municipal System .. 6-4
6 3 Private Water Systems · · ..,, · 6-6
WATER USE AND AVAILABLE SUPPLY ............................ 7-1
7.1 Existing and Future Water use ........................ 7-i
7.1.1 Residential Use ............................... 7-!
7.1.2 Agricultural Use .............................. 7-3
7.1.3 Total Water Use ............................... 7-3
7.2 Available Groundwater Supply ......................... 7-6
7.3 Water Balances ....................................... 7-9
7.4 Well Yields and Spacing Considerations ............... 7-9
7.4.1 Well Yields .................................... 7-9
7.4.2 Well Spacing .................................. 7-t2
8 0 WATER SUPPLY ALTERNATIVES · . . 8-1
8.1 Water Demand Centers ........................... . . . . .. 8-1
8 2 Water Supply Concepts ' .. . . ......o 8-4
'8.2.1 Level I Alternatives .......................... 8-5
8.2.1.1
8.2.1.2
8.2.1.3
8.2.1.4
8.2.1.5
8.2.1.6
Home Treal:nent Units ................. 8-5
Bottl ed Water ........................ 8-6
Local Delivery of Bulk Water ......... 8-6
Local Supply of Bulk Water (With
Trea tmen t) ........................... 8-6
Individual Home Wells ................ 8-6
Level I. Cost Estimates ............... 8-7
8.2.2
8.2.3
8.2.4
8.2.5
Level II--Neighborhood Systems ................ 8~12
Level II~--SubdemanU Center System~ ........... 8-I3
Level-IV--Subregional Systems ................. 8-15
Level V--Regional Systems ................... ... 8-15
Table 8-3
Table 8-4
Table 8-5
Table 8-6
Table 8-7
Table 8-8
Table 8-9
Table 8-i0
Table 8-11
Table 8-12
Table 8-13
Table 8-14
Table 8-15
Table 8-16
Table 8-17
Table 8-18
Table 8-19
Cost Estimate--Individual Home :~'ell Systems
(No Treatment) ....................................... 8-8
Cost Estimate--Individual Home Well Syst~s
(With Treatment) .................................. . . 8-10
Level V Alternatives ................................ 8-18
Components of Alternatives Levels II Through V ...... 8-22
Example of Cost Determination for Alternatives ...... 8-25
Estimated Annual Dwelling Unit Costs of
Water Supply Alternatives for the Wading River/
Northville Demand Center ........
8-29
Existing Public Water Systems in the Wading
River/Northville Demand Center ...................... 8-31
Capital Cost Estimates--Wading River/Northville
Demand Center ....................................... 8-34
Estimated Annual Dwelling Unit Costs of Water
Supply Alternatives for the Riverhead/Jamesport
Demand Center ....................................... 8-36
Capital Cost Estimates--Riverhead/Jamesport
Demand Center 8-40
Estimated Annual Dwelling Unit Costs of Water Supply
Alternatives for the Mattituck/Cutchogue
Demand Center ....................................... 8-43
Level III Alternative Components for the
Mattituck/Cutchogue Demand Center .................. · 8-45
Summary of Level V Alternative Components for the
Mattituck/Cutchogue Demand Center .................. . 8-49
Capital Cost Estimate--Mattit~ck/Cutchogue
Demand Center ....................................... 8-52
Estimated Annual Dwelling Unit Costs of Water
Supply Alternatives for the Southold/Greenport
Demand Center ' 8 53
Level III Alternative Components for the Great
Hog Neck and East Marion Subdemand Centers .......... 8-64
Cost Estimates--Greenport/Southold Demand
Center .............................................. 8-66
8.3 Water Treatment Processes .................. 8-17
8.3.1 Ion Exchange/Carbon Adsorption ................ 8-19
8.3.2 Reverse Osmosis .............................. . 8-20
8.4 Alternatives for Demand Centers ...................... 8-21
8.4.1 General
8.4.1.1
8.4.1.2
8.4.i.3
8.4.1.4
Development Criteria .................. 8-21
Supply ............................... 8-21
Transmission/Distribution ............ 8-23
Treatment ............................ 8-24
Annual Operation and Maintenance ..... 8-24
8.4.2 Development of Cost Estimates ................. 8-2C
8.4.3 Wading River/Northville ....................... 8-26
8.4.3.1
8.4.3.2
8.4.3.3
Level I Alternatives ................. 8-26
Level II Alternatives ................ 8-30
Level III Alternatives ............... 8-30
8.4.4
Riverhead/Jamesport ........................... 8-35
8.4.4.1
8.4.4.2
8.4.4.3
Level I Alternatives ................. 8-35
Level II Alternatives ................ 8-35
Level III Alternatives 8-39
8.4.5
Mattituck/Cutchogue ......................... . . 8-39
8.4.5.1
8.4.5.2
8.4.5.3
8.4.5.4
8.4.5.5
Level I Alternatives ................. 8-42
Level II Alternatives ................ 8-42
Level III Alternatives ............... 8-42
Level IV Alternatives ................ 8-46
Level V Alternatives ................. 8-46
8.4.6
Southol d/Greenport ............................ 8-51
8.4.6.1 Level I Alternatives ................. 8-51
8.4.6.2 Level III Alternatives ............... 8-51
8.4.6.3 Level IV Alternatives ................ 8-61
8.4.6.4 Level V Alternatives ................. 8-61
8.4.7 OPient ........................................ 8-68
8.4.7.1-
8.4.7.2
8.4~7.3
Level I Alternatives ................ . 8-65
Level III Alternatives ............... 8-65
Level IV and V Alternatives .......... $-68
8.4.8 Isolated Neighborhood Systems ................. 8-69
Table 8-20
Table 8-21
Table 8-22
Table 8-23
Table 8-24
Table 8-25
Table 8-26
Table 8-27
Table 8-28
Table 8-29
Table 9-1'
Estimated Annual Dwelling Unit Cos~ of Water
Supply Alternatives for the Orient Demand Center .... 8-65
Capital Cost Estimates--Orient Demand Center ........ 8-68
Estimated Costs of Water Supply Alternatives
for Isolated Neighborhood Systems ................... 8-70
Capital Cost Estimates--Neighborhood Systems ........ 8-71
Comparison of Alternatives--Wading
River/Northville Demand Center ...................... 8-75
Comparison of Al ternatives--Riverhead/Jamesport
Demand Center ....................................... 8-76
Comparison of Alternatives--Mattituck/Cutchogue
Demand Center ....................................... 8-77
Comparison of Al ternatives--Greenport/Southold
Demand Center ....................................... 8-78
Comparison of Alternatives--Orient Demand Center .... 8-79
Comparison of Alternatives--Isolated
Neighborhood Areas · 8 80
Summary of Capital Costs for the Recommended Plan... 9-2
(SPHS/26
8.5 Comparison of Alternatives ........................... 8-69
8.5.1
8.5.2
8.5.3
8.5.4
8.5.5
8.5.6
Cost .......................................... 8-69
Rel iabil ity ................................... 8-72
Impl ementabil ity .............................. 8-72
~nvironmental Considerations .................. 8-73
Adaptability to Future Changes ................ 8-73
Summary Comparative Matrices .................. 8-7~
9.0 RECOMMENDED WATER SUPPLY PLAN ............................. 9-1
9.1 Wading River/Northville ....
9.2 Riverhead/Jamesport ........
9.3 Mattituck/Cutchogue ........
9.4 Southold/Greenport .........
9.5 Orient .....................
9.6 Isolated Areas .............
9.7 Groundwater Management .....
................. 9-i
................. 9-3
................. 9-3
................. 9-4
................. 9-5
9-5
10 0 IMPL~£NTATiON PLAN - 10 t
10. i Implementation Agencies ............................. · !0-1.
10.2 Potential Funding Sources ............................ 10-4
10 3 Legislative Requirements 10 5'
(SPH5/26)
LIST OF FIGURES
2-1
Study Area--North Fork Water Supply Plan ................. 2-3
4-t Geologic Cross-Section ................................... 4-3
5-1 Nitrate Contamination Areas 5 3
5-2 Aldicarb Contamination Areas. . 5 7
6-1 Existing Water Supply Systems ............................ 6-2
7-1 Water Budget Area ........................................ 7-7
8-1 Major Demand Centers ..................................... 8-2
8-2 Level III--Subdemand Center Systems ...................... 8-14
8-3 Level IV--Schematic of Subregional Systems ............... 8-17
8-4 Average Construction Cost Breakdown ...................... 8-27
8-5 Piping Cost Per Dwelling Unit at Various Housing
Densities ................................................ 8-28
8-6 Level III Alternative Components for Wading
River/Northville ......................................... 8-32
8-7 Levels III and IV Alternative Components for
Calverton ................................................ 8-37
8-8 Level III Alternative Components for Jamesport ........... 8-38
'8-9 Level III Alternative Components for
Mattituck/Cutchogue ...................................... 8-44
8-10 Level V(B) Alternative Components for
Mattituck/Cutchogue and-Southold/Greenport ............... 8-48
8-11 Level Iii Alternative. Components for Great Hog Neck ...... 8-54
8-12 Level III Alternative Components for East Marion ......... 8-55
8-13
8-14
8-15
Level III Alternative Components for the
Greenport Municipal System ............................... 8-57
Schematic of Level III(B) for Greenport .................. 8-60
Level III Alternative Components for Orient .............. 8-67
(SPH5/26)
SECTION 1.0
EXECUTIVE SUM~RY AND RECOMMENDATIONS
1.1 EXECUTIVE SUMMARY
Water supply problems on the North Fork of Long Island are severe.
Shallow, thin groundwater aquifers are extensively impacted by con-
tamination from agricultural chemicals, primarily nitrates and
pesticides, and are threatened by saltwater intrusion from over-
pumping. Increasing pressures for development which will result in
accelerated population growth will further stress the water supply
aquifers.
In response to the threats to groundwater quality and the increased
demands for potable drinking water, the Suffolk County Department of
Health Services {SCDHS) sponsored a study of water supply options for
the North Fork. The objectives of this North Fork Water Supply Plan
are to develop and evaluate several alternative water supply plans
which could safely meet present and future potable water requirements
and recommend a future course of action.
The planning area includes the towns of Riverhead and Southold.
Since hydrogeologic conditions are significantly differeqt throughout
the area, five water supply zones were established for planning pur-
poses. Zone 1 starts at the western Town boundary of Riverhead and
extends easterly to the hamlet of Riverhead~ In this zone, the
Magothy aquifer is saturated with fresh water all the way to bedrock.
The presence of saltwater increases in .the lower portions of the
Magothy as one progresses east from the hamlet, until the fresh water
lens terminates at Mattituck Inlet, which is the eastern boundary of
Zone 2. Zones 3, 4 and 5 are defined by three isolated fresh ground-
water lenses. Zone 3 extends from the Mattituck Inlet, to Hasha--
momuck Pond; Zone 4 extends from Hashamomuck Pond to Dam Pond; Zone 5
starts at Dam Pond and continues through Orient Point.
Area Characteristics
-The Long Islahd Regional Planning Board estimates that permanent
population in the study area will increase fr~_ approximately 391,0Q0
today _to 49,800 in the year 2000. On a peak summer_weekend, an addi-
tional 32,000 persons.are anticipated.
Agricultural land use is the most prevalent in the study area today,
accounting for approximately 42 percent of the land area (29,560
acres); current residential land use accounts for 12 percent of the
area. Future land use projections by the Regional Planning Board
indicate that low-density residential development will significantly
increase in both Towns, while agricultural usage will decrease. The
land use trends projected by the Planning Board forecast a decline in
agricultural land of approximately 18 percent (5,300 acres). Fur-
thermore, the Cooperative Extension Service anticipates a gradual
change in the types of crops grown on the North Fork. In general,
potatoes, sod and rye acreage will decrease while grapes, mixed
vegetables, horse farms and nursery stock will increase in acreage.
Groundwater Quantity
The major geologic units in the two towns are bedrock, the Raritan
Formation, the Matawan Group {Magothy Formation aquifer) and
Pleistocene deposits (glacial deposits including the upper glacial
aquifer).
The principal water supply source in the study area is the upper
glacial aquifer. It is a highly productive water-bearing unit with
consistent physical properties.
In the eastern part of water supply Zone 2 and in zones 3, 4, and 5,
a very delicate balance exists between fresh groundwater lenses,
saltwater intrusion, chemical contamination and water supply require-
ments. The fresh groundwater lenses are relatively thin; therefore,
the total available supply is limited. Over-pumping or improper well
location causes lateral and vertical saltwater intrusion. The aqui-
fers are extremely susceptible to chemical contamination because they
are shallow and have limited dilution or assimilative capacity.
Groundwater flow velocities are very low (on the order of one foot
per day) so it takes long periods of time fQr contaminants to flush
out of the aquifer (up to 100 years). These conditions mandate that
groundwater resources be properly managed and protected in order to
be able to support necessary water supply requirements.
Consumptive water use patterns will change in the ~tudy area over the
next 20 years. Domestic requirements (including commercial and in-
dustrial) will increase by 25 percent from an annu~ average of ap-
proximately 4 million gallons-per day (mgd) today .to over 5 mgd in
the year 2000. Agricultqral usage, however, will decline-by 18 per-
cent from 11 mgd to 9 mgd. During summer months, domestic usage is
expected to be over 6 mgd; ~gricultur~l consumption'will be approxi~
mately 22 mgd~ The trend to residential development from agriculture
will result in a slight overall decline in average daily water use
over the planning period, but the demand for uncontaminated, potable
water wil) increase.
In order to estimate the total quantity o~ groundwater that may be
withdrawn from larger capacity public supply wells from each water
supply zone, water budget-areas were delineated. Substantial amounts
of groundwater are available outside of the budget areas but, to
avoid saltwater intrusion, can only be withdrawn by small, domestic
capacity wells.
In zones 1 and 2, the budget areas were defined as those locations
where the groundwater level is 5 feet or more above sea level. In
zones 3, 4 and 5, the availability of groundwater is more limited, so
the budget area boundary was defined as the 2-foot groundwater con-
tour. A total of approximately 41.2 mgd of fresh groundwater is
available from the budget areas. An additional 10 to 20 mgd is
available for domestic wells outside the budget areas. The results
of the water budget analysis, by zone, are shown below in Table 1-1,
which also includes consumptive use projections for the year 2000.
Conclusion. Sufficient fresh groundwater is available to satisfy the
needs o~ she overall planning area. However, critical water supply
conditions exist in Zone 5 (Orient) where projected requirements are
approximately equal to available supply. Groundwater supply condi-
tions in Zone 4 (Greenport/Southold) are also critical although there
is some extra available supply (0.9 mgd available versus 0.63 mgd re-
quired).
TABLE 1-1
WATER BUDGETS AND CONSUMPTIVE USE PROJECTIONS
Permissive Domestic Agricultural
Water Sustained Yield, Consumptive Use, Consumptive Use,
Supply Budget Area Year 2000 Year 2000
Zone (mgd) (mgd) (mgd)
1 29.4 2.25 3.06
2 5.6 0.97 3.06
3 4.9 1.18 2.80
4 0.9 0.59 0.04
5 0.4' 0.11 0.35
TOTALS 41.2 5.10 9.31
1-3
Groundwater Quality
The upper glacial aquifer throughout the planning area is already
contaminated with nitrates and organic pesticides and herbicides.
Nitrate levels are significantly elevated above natural background
conditions of 0.1 to 1.0 milligrams per liter (mg/1) and exceed the
drinking water standard of 10 mg/1 in many areas. Sampling of 639
wells for nitrates performed by SCDHS in the Town of Riverhead showed
the following: 58 percent of the samples ranged from 0 to 5 mg/1; 26
percent were above 7.5 mg/1; and 16 percent were above 10 mg/1.
Similar results were obtained in a sampling of 1,121 wells in the
Town of Southold; 51 percent of samples ranged from 0 to 5 mg/1; 30
percent were above 7.5 mg/1; and 17 percent were above 10 mg/1.
Organic contamination from pesticides and herbicides is also wide-
spread. A comprehensive survey to define the extent of contamination
from one pesticide--Aldicarb--was conducted by the SCDHS in 1979 and
1980. In the Town of &iverhead, 2,161 wells were sampled; 32 percent
were contaminated by Aldicarb; 16 percent had Aldicarb concentrations
above the health guideline of 7 parts per billion (ppb). In the Town
of Southold, 3,160 wells were sampled; 23 percent showed Aldicarb
contamination; 11 percent exceeded the health guideline of 7 ppb.
Numerous other agricultural chemicals have also been found including
carbofuran, dacthal, dichloropropane, oxamyl and dinoseb.
Nitrate contamination is vertically extensive throughout the upper
glacial aquifer. Aldicarb and other organics are presently limited
to the upper 40 feet of groundwater; however, they are expected to
distribute throughout the aquifer over time. Since velocities of
flow are on the order of 1 foot per day in the North Fork aquifers,
contaminants will be present for many decades before they are ~ushed
Out.
The amounts of uncontaminated groundwater avail able for consumption,
although not quantifiable, are substantially less than those shown in
Table 1. When groundwater flow is considered, almost all of zones 3,
4 and 5 become suspect as well as the upper 50 feet of groundwater in
zones 1 and 2.
Conclusion. Groundwater contamination is currently extensive and
w~)) remain so for many years. As additional groundwater quality
data is collected, more contamination problems will be discovered.
Water supply implemehtation for the North Fork must proceed im-
mediately. Alternative solutions must consider the fact that the
limited volume of fresh groundwater is further limited because large
portions have been contaminated by agricultural chemicals.
I-4
Water Supply Alternat,i.¥es
There are several levels of development, on the 1;orth Fork, all of
which had to be considered in the ~lanning process. Five areas of
population concentrations were defined as major water supply demand
centers: (1) Wading River/Northvi~le, (2) Riverhead/Jamesport, (3)
Mattituck/Cutchogue, (¢) Southold/~reenport, and (5) Orient. Dis-
tinct individual communities (e.g.j Calverton, Little Hog NecK, East
Marion) comprise the demand centers. The remaining areas were con-
sidered low-density residential and rural and were considered
separately.
The development of alternative water supply plans to serve this broad
spectrum of needs proceeded in a b~ilding block fashion, beginning
with an evaluation of individual h~me wells through community systems
to large, regional systems. Five levels of water supply alternatives
were developed and evaluated:
Level I:
Level 1I:
Level III:
Level IV:
Level Y:
Individual Home SyStems--In areas where groundwater
is degraded, theselwould include treatment of the
home supply.
Neighborhood Systems--These are small municipal sys-
tems serving two tb 50 homes.
Community Systems-~l"nese are systems serving indi-
vidual communitiesl with local groundwater.
Subregional System~--These are larger systems serving
an entire demand c~nter with local groundwater.
Regional Systems--Wherein the supply is uncontamin-
ated groundwater f~om Riverhead piped via a major
transmission main Ito the eastern portions of the
study area.
In addition to the above listing, ~ual water supply systems, bottled
water, clean water vending machines, trucK-delivered water and cen-
tral, com~unit~ .water supply taps twere al so evaluated as part of this
study. I
Preliminary engineering-studies a~d designs were developed for each
m
~lternative. C~pital cost estimaqes were prepared and annual amorti-
zation and operation/ma~ntenance/~dministr~tion costs were also esti-
mated. The cost estimates ranged)from $15~ per-year per hom~ for-in~
dividu~l home wells in areas wi-th)potable groundwater to over
per y_ear per home where exteQsive Itreatment is necessary or where
clean groundwater has to be imported. Because o~ low.density devel-
opment, the relative costs of distribution systems are extremely high
and preclude the developme?t of municipal systems in some areas.
: -1_-5 '- - -
Commerical and industrial water usage was not included in the
development of per home costs. Although t~is represents a small
fraction of the total, the inclusion of the commerical and industrial
base would reduce the cost per home.
In addition to comparing the costs of alternatives, several other
factors were considered in the screening and evaluation process:
(1) Reliability of operation
(2) Environmental consequences
(3) Implementation problems
(4) Flexibility to respond to future problems.
Conclusion. The study found that a combination of residential public
water systems and individual home treatment units is essential. Some
form of direct governmental involvement is needed for implementation.
Implementation
Under the provisions of New York State l~w, there are four institu-
tional entities that could implement all .or portions of the selected
alternatives: villages, towns, counties and the Suffolk County Water
Authority.
Implementation at the town level will give local government the abi-
lity to provide public water systems in response to the needs and
desires of the people. Expenditures and cash flow would remain in
the control of the towns and they would retain a great deal of flexi-
bility in the types of public water supply facilities to be provided
for individual areas.
Mai.or legislation 'at th~ County or State level is not required if the
towns implement the study's recommendations. It will be necessary,
however, to amend existing State legislation in order to define home
treatment units as water supply facilities, rf the towns do not
choose to implement, the County would have to consider creating water
districts for implementation; the County could, operate the districts
or contract to the Suffolk County Water Authority. County implement-
a~ion would require !egislative action at t~e County .level.
This.investigation also-included an analysis of (unding s~ur~es to
assist in implementing the reco~endations. No such s~urces were
found which are currentlT-funded. Thus, the improvements will have
to be paid for at the local level, primarily through user charges.
Conclusion. The towns of Riverhead and Southold can best implement
the stuOy's recommendations: (1) by forming town Water Management
Programs, as administrative functions, to coordinate all water supply
activities in the respective towns, {2) by forming Water Supply Dist
ricts or extending existing district boundaries to purchase, own and
operate private water companies or to construct new public water sys-
tems, and {3) by forming Home Treatment Unit Districts (covering all
or portions of the town area not served by public water) and owning
and maintaining the home units. {The towns may allow private industry
to sell home treatment units after approval of the units by the town,
but the town should retain maintenance responsibility.)
1.2 RECOMMENDATIONS
General Recommendations
This study has demonstrated conclusively that numerous technical
and financial difficulties are encountered when attempting to
provide potable water to the residents of the North Fork. Pre-
ventive measures to minimize or eliminate additional groundwater
contamination must be implemented. These measures are not
immediate solutions to current water supply problems but are
desireable and necessary long-torm actions.
(2)
Because of severe groundwater quality problems in the study
area, a safe, dependable water supply must be provided to the
residents of the North Fork. A combination of individual home
treatment units plus public water systems should be implemented.
(3)
The towns of Riverhead and Southold should individually assume
responsibility for implementing water supply programs within
their boundaries. Administratively, the towns should establish
Water Management Programs, Water Supply Districts and/or water
improvements encompassing parts of, or the entire areas of, the
towns, for implementation of the plans and recommendations of
this study. As an incorporated village, Greenport cannot be
included in the Southold District unless it petitions the Town
for inclusion.
(4)
The personnel operating the water systems in the hamlet-of
Riverhead and Village of Greenport have technical and adminis-
trative water supply expertise which can be utilized by the
towns. Since the Riverhead system is currehtly a part of Town
government, institutio'nal arrangements would not be required to
utilize this expertise. In Southold, the Town can do the fol-
lowing: establish its own water supply staff; contract wi.th
Greenport for personnel services beyond those currently provided
by the Village; or employ a combination of Town staff and
Village services.
1-7
(5)
(6)
(7)
(8)
(9)
The town Water Management Programs should include individual
home treatment as part of their overall responsiblities as Home
Treatment Unit Districts. In order to ensure safety and reli-
ability, the town Home Treatment Unit Districts {not the home-
owner) should own, operate and maintain the home treatment
units, not the homeowner; private enterprise can al so be allowed
to supply units, as approved by the towns, but the towns should
retain maintenance responsibilities.
In areas of existing development where groundwater is contamina-
ted, the Water Management Programs should provide public water
systems, if economically feasible, through Water Districts. If
public systems cannot be implemented, home treatment units
should be publicized and recommended by the water programs and,
if existing homeowners request service, the program should
provide, own and maintain the home units.
When new subdivisions are proposed in areas of groundwater con-
tamination or potential contamination, connection to existing
public water supplies of adequate capacity are required. If
such supplies are not available, then new public supplies are to
be constructed by the developer and deeded to a town Water Dist-
rict.
If an existing home is sold in an area of suspected groundwater
contamination, the SCDHS or other appropriate agency should
sample and test the home well and the results should be attached
to the deed. If the water quality does not meet standards, the
current homeowner should make provision through the Water
Management Program to provide a safe water supply prior to the
sale of the home.
The SCDHS is planning to locate a vending machine in the study
area which will purify local groundwater and sell the purified
water at a nominal cost. If the concept is accepted by the
citizens of the area, other vending machines should be located
by the Water Management Programs throughout the area as interim
measures until the other recommendations of this study are
implemented.
Area-Specific Recommendations
(1o)
Wading River/Northville--The existing individual water systems
in Wading River, Baiti'ng Hollow/Woodcliff Park and Reeves Park
should be connected to new supply wells which will separately
serve each of the three individual subsystems. This is neces-
sary to improve the reliability of the supply and to assure
potable water. The new facilities also should De located and
sized to serve areas which do not currently nave public wa~er
systems but the new service areas should be developed in a
phased approach.
(11)
(12)
(13)
The Riverhead Town Water District should own and operate the new
supply wells and transmission lines, and should sell water to
the individual water systems through metering facilities. If
any of the private systems want to deed their facilities to the
Town, the Water District should accept them.
It is not economically feasible to provide public water systems
to the remainder of the area; these residents should continue to
be served by individual home wells, with treatment as required,
provided by a Home Treatment Unit District.
Riverhead/Jamesport--?he Riverhead system should be extended to
serve the Calverton area and should actively attempt to further
expand its system to other areas adjacent to the present system.
Major improvements are not required in the Riverhead system ex-
cept for additional distribution system storage. The remainder
of the area, including Jamesport, should continue to be served
by individual home wells with treatment as required, since it is
not economically feasible to serve those areas with public water
facilities.
Mattituck/Cutchogue--The Town of Southold should acquire and
operate the existing water system in Mattituck Hills (Captain
Kidd); measures should be taken (mmediately to upgrade the
performance and reliability of the system and to augment its
source of supply~ In the remainder of the Mattituck/Cutchogue
demand center {including Cutchogue, Mattituck, Little Hog Neck,
East Cutchogue, Fleets Neck, New Suffolk and Indian Neck) it is
not economically feasible to provide public water supply sys-
tems. These areas should continue to utilize individual home
wells; when treatment is required, it should be provided through
the Home Treatment Unit District.
SoutholdlGreenport--The Greenport Municipal System, which pre-
sently'serves Greenport and parts of Southold, should continue
to rely on local groundwater sources. However, major improve-
ments to the system are required. An agricultural well on
County Rt. 48 (on the Donohue Farm) should be upgraded (450-gp~
total capacity) and used for public water supply. A 2.2-mgd
reverse osmosis treatment plant should be constructed in stages
to tPeat the water from the Donohue Well and existing plants no.
6 and 7 used for removal of nitrates,.pesticides and herbicides.
After implementing the improvements, the Greenport system should
actively attempt to'further expand into other areas adjacent to
the existing sysfem. Such_expansion should not be ~ermitted,
however, until the redommehded modifications have been com- --
pleted.
(14)
(15)
16)
The activities of any town Water Districts should not impact the
existing customers of the Greenport system who are located in
the Town; their charges should only reflect the costs of operat-
ing the present Greenport system after it is upgraded.
In the remainder of the Greenport/Southold area, including Great
Hog Neck and East Marion, it is not economically feasible to
provide public water supply systems. These areas should con-
tinue to be served by individual home wells, with treatment as
required, provided through a Home Treatment Unit District.
Orient--The Orient area, with its relatively low density of
development, cannot economically support public water supply.
Existing development should continue to be served by individual
home wells with treatment as required. The available fresh
water supply is limited and future development should be tightly
controlled and result in water requirements consistent with the
permissive sustained yield of the aquifer in Zone 5. It is
further recommended that only variances resulting in less water
usage be approved. If future development is more water-use
intensive, the permissive sustained yield in the area will be
exceeded and other more costly solutions will be neeOed.
Neighborhood Systems--Public water systems for existing isolated
neighborhoods in areas of groundwater contamination are gener-
ally not economically feasible. Therefore, it is recommended to
continue to serve these areas by individual home wells, wish re-
quired treatment provided through a Home Treatment Unit Dist-
rict.
Regional Pipeline System--The development'of a major supply of
uncontaminated groundwater in eastern Riverhead anO piping it
via a major transmission main to the eastern portions of the
study area was a major alternative considered in the study.
ds not recommended for the following reasons:
(a)
(b)
The pipeline would encourage levels of development which
appear to be inconsistent with the current life style of
the peop)e and the general character of the area.
The construction'of such a pipeline'would require the early
commitment of major financial resources and resolution of
numerous institutional issues. Both types of problems
would require a great deal of time for resolution; the
water supply problems of' the North Fort cannot tolerate
significant delays,
(c)
The pipeline alternative is economically competitive with
treating local sources of groundwater in Mattituck, Cutch-
ogue, Greenport and Southold only if an uncontaminated
supply can be found in the Mago--6-{ffy aquifer, below the clay
layer and above the saltwater interface in eastern River-
head. Preliminary data indicates such a supply exists, but
its extent and yield needs to be verified with pump test
information. To move further west in Riverhead into the
Peconic Valley, where clean groundwater is known to exist
in sufficient quantity, is not economically competitive
with treating local sources of supply.
Preventive Measures
(17) This plan has identified numerous technical and financial prob-
lems associated with providing water supply to areas of the
North Fork where groundwater is contaminated. Preventive
measures must be undertaken in parallel with recommendations 2
through 16 in order to eliminate or minimize additional con-
tamination. The following preventive measures are recommended:
(a)
(b)
(c)
(d)
(e)
(f)
(g)
Expand the SCDHS observation well network and home well
sampling program.
Support the Cooperative Extension Service, Cornell Univer-
sity and U.S. Depar~ent of Agriculture (USDA) research and
education programs directed to the homeowner and farmer
relative to usage, dosages and timing of application of
herbicides, pesticides and fertilizers.
Support the testing of agricultural chemicals by State or
federal agencies in the local environment as a precondition
to use by the farm community.
Prohibit or control the sale or use of products and chemi-
cals which threaten the groundwater resources.
Control industrial, commercial and residential activities
which impact negatively on groundwater quality.
Incorporate detailed water quantity and quality considera-
tions into rezoning and variance decisions..
Encourage water conservation through public information
programs and require water-saving fixtures in new home con-
struction.
1-11
Continue public information and education programs ~o
emphasize the fragile nature o~ She area's water supply and
to foster cooperation in the solutions to those problems.
(98/4)
1-12
SECTI ON 2.0
INTRODUCTI
2.1 SCOPE
The water supply aquifers of the North Fork are threatened by several
sources of contamination. Agricultural chemicals used on the land
eventually find their way into the aquifers as demonstrated by the
elevated nitrate and pesticide (Aldicarb) levels found in the upper
glacial materials. In addition, over-pumping and incorrect well
location can induce saltwater intrusion into the aquifers.
Changing land use patterns further exacerbate the water supply prob-
lems. As agricultural lands are converted to residential and commer-
cial use, the need for potable drinking water increases. Planning
officials have predicted that the trend from agricultural to residen-
tial development will continue over the next 20 years, so the demand
for potable drinking water will continue to grow.
In response to the threat to groundwater quality and the increased
demands for potable drinking water, the Suffolk County Department of
Health Services {SCDHS) initiated a study of water supply options for
the North Fork. The objective of the North Fork Water Supply Plan is
to develop and evaluate several alternative water supply plans which
could safely meet present and future potable water demands. This was
accomplished in three phases.
Phase I consisted of an analysis or present and future population
levels and land uses. Present water consumption patterns were also
evaluated to develop a complete understanding of water supply systems
needs and to accurately project future water supply demands. Simul-
taneously, hydrogeologic studies were performed to develop estimates
of the quantities of fresh groundwater available and to ascertain the
extent and degree of contamination of the grgundwater by organic and
inorganic constituents.
The background-investigations formed the basis upon which alterna~ve
plans were developed and evaluated in Phase.II. Alternative re-
gional, subregdonal and community water supply concepts were identi-
fied and developed. These were then evaluated on the bas'is of cost,
environmental consequences, reliaDility of operation, and f]exibi) i~y
to determine a future course of action. -
In Phase III legislative, management and financing constraints were
stu'died and suitable recommendations for implementation were
developed.
2-1
.1
.l
2.2 STUDY AREA
The plan covers the towns of Riverhead and Southold on the ~or~h Fork
of Long Island (see figure 2-1). The North Fork is essentially a
peninsula which extends east for over 35 miles from the eastern
terminus of the main land body of Long Island. The study area ex-
tends from the community of Wading River on the west to Orient Point
on the east, and covers approximately 109 square miles. It is bound
on the north by Long Island Sound and on the south by the Peconic
River and Peconic Bay. Offshore islands were not included in this
study.
2.3 PLANNING APPROACH--WATER SUPPLY ZONES
As one progresses west to east through the study area, groundwater
availability changes significantly. From the standpoints of planning
and implementation, it is logical to organize the study area into
discrete groundwater supply zones for analysis. Five such zones were
defined {see Figure 4-1).
Zone 1 starts at the western Town boundary of Riverhead and extends
east to the area of the commercial hamlet of Riverhead. In this
zone, the Magothy aquifer is saturated 'with fresh water all the way
to bedrock. Doctor's Path is-used as the eastern terminus of Zone 1.
In the hamlet area, saltwater becomes evident in bhe lower depths of
the Magothy. The presence of saltwater in the Magothy increases as
one progresses east, until the fresh water lens terminates at
Mattituck Inlet, which is the eastern boundary of Zone 2.
Zones 3, 4 and 5 are defined by the east-west boundaries of three
isolated fresh groundwater lenses. Zone 3 extends from the Mattituck
Inlet to Hashamomuck Pond. A fresh water lens begins at the Inlet,
increases in depth in an easterly di6ection, and then ends where the
ground surface intersects the groundwater table at the.Pond and salt-
water intrudes. Zone 4 extends from Hashamomuck Pond to Dam Pond;
Zone 5 starts at Dam Pond and ends at Orient Point.
Each zone has its own hydrogeologic characteristics and water Dudget.
There is some fresh water movement between zones 1 and 2; the other
three function independently. Contamination problems vary among the
zones and there are substantially different volumes of fresh water
available in'each zone. -In other words, each zone is unique, and i~s
distinguishing features have to be considered. Therefore, all basic
inventory data was drganized by zone, and the development and evalua-
tion of alternatives al-so considered the zone boqndaries..
(98/5)
2-2
INSERT FIGURE 2-1
2-3
SECTION 3.0
POPULATION AND LA~D USE
3.1 POPULATION
The U.S. Census indicates that the year-round population of the North
Fork study area was 39,Dg7 in 1980; 20,243 people resided in the Town
of Riverhead, and 18,854 in the Town of Southold {excluding Fishers
Island, which is outside the study area). As shown in Table 3-1, the
population reached these levels after growing 7 and 15 percent,
respectively, in Riverhead and Southold during the 1970's. During
this period, almost 4,000 people were added to the two towns. Most
of the growth occurred in the Shoreham/Wading River, Southold and
Mattituck/
Cutchogue areas. Oyster Pond, Greenport, and New Suffolk experienced
minor decreases in population during the period.
Population projections developed by the Long Island Regional Planning
Board on the basis of school districts forecast continued growth. It
is anticipated that the population in Riverhead and Southold will in-
crease to 49,800 people {a 27 percent increase) between 1980 and
2000(1), with all school districts experiencing growth. The popu-
lation in Riverhead is expected to increase to 26,750 persons (a 32
percent increase) while the population in Southold is expected to
increase by 22 percent, reaching a level of 23,050. These projec-
tions represent a refinement of earlier planning board estimates
(prepared during the 208 Program), and project a lower rate of growth
in the area than that originally forecast.
Population data is presented in Table 3-2 by groundwater supply zone.
The reorganization of the data, which was based on school districts,
was accomplished with the aid of-detailed census tract data, Long
Island Lighting Company {LILCO) population estimates and planning
board population density and land use maps.
During the summer, the population on the North Fork increases signi-
ficantly. The summer.population increase consists of guests, second-
home owners, campers and motel users. The Suffolk County Planning
Board estimates that the population in Riverhead and Southold in-
creased during a peak weekend by 10,705 and 19,760 people, re-
spectively, during the summer of 1980 (see Table 3-3).
(1)Futu/e ~opula~ion, land use and water demand information in this
report is presented for the year ~000 although the planning board
data is developed for 1995. However, the timing of the projected
growth levels is not accurate, and it is entirely possible that they
will not be reached until 2000 or 2005.
N
3.2 LAND USE
Land use impacts water supply requirements since individual land uses
have different water quality and quantity needs. It was, therefore,
important to consider existing land use on the North Fork and to
examine projected future land use.
Existing land use in the two towns is summarized in Table 3-4. Wit~
the exception of Zone 4, agricultural land dominates each zone, wit~
42 percent of the land area (29,360 acres) currently devoted to agri-
cultural usage. Crops grown on the North Fork include potatoes,
mixed vegetables, cabbage, cauliflower, rye, nursery stock, fruit
trees, grapes and sweet corn.
Lower density residential development (one to four dwellings per
acre) dominates the residential land use category. High-density
residential development (greater than five dwellings per acre)
occurs significantly only in zones 1 and 4 {downtown Riverhead ano
the Village of Greenport). The vacant land category includes open
space, unmaintained parkland, and undeveloped portions of Grumman's
complex in Zone 1. Industrial development on the North Fork is ex-
tremely limited (except for Grumman). Commercial usage can be found
to a limited extent in each zone, with significant commercial devel-
opment in the hamlet of Riverhead, Greenport Village and to mlesser
extent in Mattituck and Southold.
Future land use was projected by the regional planning board during
the 208 Program. The projections indicate that low-density residen-
tial development will significantly increase in both towns, while
agricultural and open/vacant space will decrease, The land use
trends projected by the planning board forecast an 18 percent decline
in agricultural land use (approximately 5,300 acres). These projec-
tions are generally consistent with past trends, which resulted in
the loss of 30 percent of the farm land in Suffolk County between
1964 and t978. This trend is abating somewhat as the County's
Farmland Preservation Plan and open space policies are implemented.
The Cooperative Extension Service anticipates a gradual change in the
types of crops grown on the North Fork. In general, potatoes, sod
and rye acreage will decrease while the other crops grown will in-
crease in acreage.
(98/12)
3-5
SECTION 4.0
GEOLOGY
The geology of the study area has been described in several earlier
investigations. The most recent detailed geologic investigation of
the Nor~ Fork was performed by the Suffolk County Department of
Heal th Services (SCDHS). A brief summary of the stratigraphic re-
lationships found in the study area is presented below.
4.1 GEOLOGIC UNITS
4.1.1 Bedrock
Crystalline bedrock of Pre-Cambrian age underlies the entire study
area at depths ranging from 500 feet below sea level in eastern
Southold to approximately 1,300 feet below sea level in southwestern
Riverhead. The bedrock consists of gneiss and schist of very low
permeability. It has virtually no value as an aquifer.
4.1.2 Raritan Formation
Resting unconformably on the bedrock surface is the Raritan Formation
of Late Cretaceous age. This unit is generally divided into the
lower Lloyd Sand member and t~e overlying Raritan Clay member. Both
units become progessively thinner to the east. The Lloyd decreases
from a thickness of about 300 feet to 150 feet. Similarly, the Rari-
tan Clay varies from 200 to 100 feet.
The Lloyd Sand has been described as a-grayish white, coarse sand and
gravel with interbedded units of gray clay. The Raritan Clay is
described as gray clay and silty clay. Fresh water is only found in
the Raritan Formation in parts of Zone i. Generally, the water
quality and depth of the Raritan Formation make it an-unlikely source
of water supply within the study area.
4.1.3 Matawan GKoup--Magothy Formation Undifferentiated
The Magothy Formation,qike the Rarita~, is a later Cretaceous-
deposit although an erosional un6onformity ~eparates the two units~
The upper surface of the-Magothy was al~o shaped by erosion forces.
The irregular upper Magothy surface forms a circular high about. 150
feet below sea level in western Riverhead and then drops to a rela-
tively constant surface about 350 feet below sea level. The con-
figuration of the Magothy's upper surface is shown in Figure 4-1.
The total thickness of the Magothy in the study area varies from
about 150 to 600 feet.
The Magothy generally consists of gray fine to coarse sand with
interstitial silt and clay. Lenses of clay, silt and clayey sand are
also commonly found in the Magothy, particularly the upper sections.
The basal portion of the Magothy is generally coarser with coarse
sand and gravel being characteristic.
In the five western towns of Suffolk County, the Magothy is the
principal source of public water supply. Within the study area,
however, the Magothy is only available for supply in zones 1 and 2.
East of Mattituck Inlet, in zones 3, 4 and 5, the Magothy is
generally salty.
4.1.4 Pleistocene Deposits
The most important geologic unit within the study area with respect
to supplying drinking water are the glacial deposits of Pleistocene
age. This material rests unconformably on the Magothy's eroded upper
surface and reaches a maximu~n thickness of about 650 feet in north-
eastern Riverhead.
The physical properties and appearance of the glacial deposits vary
with manner of deposition. The predominant type of glacial deposit
in the study area is outwash. Deposited by glacial meltwater, the
outwash is stratified and generally composed of clean sand and
gravel. Till, the other major glacial deposit, was laid down by
moving ice, and consists of unsorted clay, silt, sand, gravel and
boulders. The till is primarily found along the north shore of the
study area.
Several previous investigations discuss the existence of a substan-
tial clay unit interbedded with the outwash deposits. As part of
this study, an attempt was made to Collect all the geologic logs
available from wells drilled in Southold and Riverhead. Based on the
correlation of these logs (wells no. A through E shown on Figure 4-1)
including recent drilling projects done by SCDHS, a continuous unit
of clay and sandy clay is shown to exist between 60 and 150-feet
below sea level. The variable thickness and horizontal extent of the
clay is shown in Figure 4-1. The clay is particularly well docu-
mented in zones 2 and 3. In these areas, every well that penetrated
deep enough encountered the clay at approximately the same elevation.
The clay was also found in zones l, 4 and 5; however, the paucity of
data makes a correlation in these areas somewhat problematic. The
complete areal extent o-f the clay, the depositional environment and
its relationship to other clays on Long Island (i.e., the Gardiners
Clay, the 20-foot clay, and the Smithtown Clay) remain to be dete-
rmined.
4-2
1
INSERT FIGURE 4-1
4.-3
]
]
J
]
]
]
]
(a) The water supplied to commercial development was included in
the per capita rate calculated for the districts; commercial
development outside of the water districts' service areas is
limited.
(b) The per capita rates for the water districts include use by
summer visitors. This use was estimated separately in areas
not served by public supplies, using a rate of 50 gpcd
extending over a 90-day period (from June through August).
The population projections presented in Section 3.0 were used to
estimate the future residential water use shown in Table 7-2. The
per capita rates were held at current levels in projecting future
use.
7.1.2 Agricultural Use
Irrigation rates required for each type of crop grown on the North
Pork as well as estimates of the total acreage devoted to each type
of crop were obtained from the Cooperative Extension Service (see
Table 7-3). The average irrigation rate was then calculated to be
140,000 gallons per acre per year. Total irrigation requirements
were developed by applying these rates to the total amount of
agricultural land.
crop irrigation is normally required from May through September.
Peak months are July and August, when 70 percent (35 percent during
each month) of the total annual irrigation demand is required. Peak
daily agricultural usage is assumed to be equal to the average daily
demand during these peak months.
7.1.3 Total Water Use
Total annual average water use {current a~nd future) was obtained by
adding the residential and agricultural usage in each zone (see Table
7-2). Currently, 15.35 mgd is used on the North Fork. Agricultural
use accounts for i1.33 mgd or 74 percent of the total annual use.
Residential water use will increase i~ the future as the population
increases. However, this increase will be offset by the decline in
water used for 'irrigation as the amount of land. in agricultural use
decreases. These-changes will result in a slight overall decline in
average daily water use over the planning period, although the demand
for potable water will in~rease.
Consumptive water use takes-place when water is used and not returned
to the groundwater system. Consumptive losses include evapotrans-
p~ration from crop and lawn frrigation and residential water not re-
7-3 .
]'
This clay unit has negative and positive water supply ramifications;
it is not, in itself, a good fresh water aquifer, but it does have an
ability to inhibit the upconing of sal~.~ater beneath high-yield sup-
ply wells. The clay unit has been shown to underlie Greenport Water
District's Plant 6, and this facility has never been affected by
elevated chloride levels even during periods of peak demand. Ground-
water modeling of the impact of prolonged dewatering at the Long
Island Lighting Company's {LILCO) proposed Jamesport plant also
indicated that saltwater upconing through the clay would not take
pl ace, al though lateral saltwater intrusion would be a problem.
4.2 AQUIFER PARAMETERS
To characterize an aquifer's ability to store and transmit water,
physical parameters including porosity, permeability (horizontal and
vertical), specific capacity, and transmissivity must be determined.
This can be done in several different ways (theoretical hydraulic
formula, lab tests, tracer tests); however, the most accurate method
for evaluating local aquifer performance is through a carefully
monitored pump test. The data available from pump tests conducted in
the study area are somewhat limited and variable, but enough informa-
tion does exist to generally establish the average aquifer proper-
ties.
One of the first attempts to empirically determine aquifer parameters
was a series of pump tests conducted throughout the County as part of
the Suffolk County Test Well Program. This included three individual
sites in Riverhead where six different screen settings in the Magothy
and one setting in the upper glacial were tested. In Southold, two
upper glacial settings were also tested. The results-of this work
are presented in the "Comprehensive Public Water Supply Study--Suf-
folk County, Volumes II and III" (Holzmach6r, McLendon and Murrell,
1970).
A theoretical analysis of aquifer parameters that relied on existing
data was presented in "Water Transmitting Properties of Aquifers on
Long Island, New York" (McClymonds and Franke, 1972, USGS Profes- '
sional Paper 627-E). The regional variations in hydraulic conducti-
vity and transmissivity were estimated using specific capacity and'
lithologic data.
A detailed'analysis of-aquifer properties in the study area is con-
-tained in the-1975 Geraghty and Miller report "Study of Groundwater
Condition on the Long Island Lighting Company Tract, Jamesport, New
York." As part of this study,_several pump tegts in the upper
glacial aquifer were perf6rmed'to determine the impact of ~rojectea-
heavy groundwater withdrawals.
Most recently, a pump test was run in the upper glacial aquifer at a
site near the Village of Southold as part of the Nassau-Suffolk Re-
gional Planning Board's 208 Program. The pump test results are sum-
marized in the 1977 Woodward Clyde report "Groundwater Studies for
Section 208 Plan, Long Island, New York."
Table 4-1 presents a summary of the upper glacial aquifer parameters
determined during the studies cited above.
The upper glacial aquifer is a highly productive unit, with physical
properties that are relatively consistent throughout the study area.
The uniform composition of the glacial outwash deposits in which all
the aquifer test wells were screened makes average parameter values
applicable over the entire extent of the aquifer. The variation in
specific capacities reject differences in well construction and
pumping rates as well as aquifer lithology. The differences in
transmissivities are the product of changes in aquifer thickness
(transmissivity: hydraulic conductivity x saturated aquifer thick-
ness).
The Magothy aquifer pump test data developed during the Suffolk
County Test Well Program are summarized in Table 4-2. The sites
tested are all in zones 1 and 2 where the Magothy is actually
available for water supply. Because the Magothy deposits and thedr
physical properties vary considerably both horizontally and verti-
cially, it is not as easy to make regional extrapolations from these
data.
McClymonds and Franke {1972) estimated that the Magothy in Riverhead
has a hydraulic conductivity of about 400 gallons per day per square
foot (gpd/sq ft) and a transmissivity of 260,000 gpd/sq ft based on
an aquifer thickness of 650 feet.
Although the Magothy is generally composed of finer-grained material
and is less permeable than the upper g)acial, the data-in Table 4-2
indicates that it is capable of supplying large quantities of water.
The Osborn Avenue well _in Riverhead is screened in the Magothy and is
currently used for public supply by the Riverhead Water D~strict.
Any interpretation of the data in Table 4-2 must consider that the
well screens were intentionally loQated in the most permeable hori-
zons and hot in strata that are necessarily representative of the
entire aquifer. In general, the transmissign of water in the Magot~y
in zones i and 2 is not-a limiting factor to.the development of
public water supplies.
4.3 FRESH WATER-SALTWATER ~INTER~ACE
The configurations of the fresh water lenses beneath groundwater
supply zones 3, 4 and 5 are in dynamic equilibrium with the saltwater
that surrounds them. Their thicknesses and lateral extents remain
4-5
stable over time because of the balance between recharge and dis-
charge. The location of the fresh water-saltwater interface, the
boundary be%ween the fresh water lenses and the underlying saltwater,
also tends to remain unchanged as long as the aquifer is not over-
pumped.
The position of the interface has been determined during exploratory
drilling on various projects by SCDHS, test well installations
associated with the 208 Program and CPWS-2¢, miscellaneous test ~lls
(i.e., S189, S490) and private supply wells that were inadvertently
screened in saltywater. (For the purpose of this study, saltwater
is assumed to have a chloride concentration of more than 250 milli-
grams per liter (mg/1.) This information, in conjunction with esti-
mates based on the Ghyben-Herzberg principle, were used to locate the
position of the interface on an east-west longitudinal cross-section
of the study area. The location and elevation of the interface is
shown on Figure 4-1.
The Ghyben-Herzberg relationship states that the distribution of
fresh and saltwater at hydrostatic equilibrium is caused by the
difference in density between fresh and saltwater. Based on this
difference, the depth of fresh water below sea level is predicted to
bq 40 times the height of fresh water above sea level. This re-
lationship is theoretical and when applied to the North Fork, Cran-
dell ("Geology and Groundwater Resources'of' the Town of Southold,
Suffolk County, 1963, USGS Water Supply Paper 1619-66) found that it
consistently underestimates the actual depth of available fresh
water. However, in a hydrologically sensitive area such as this, a
conservative approach is appropriate for water supply planning and,
therefore, Ghyben-Herzberg was used.
The position of the interface, deviates from the predicted location in
some areas because of lithology. The interface is found below the
clay unit throughout Zone 3, and in many areas this is much deeper
than would be expected. The thick, nelatively impern~eable clay unit
apparently prevents the interface or the associated zone of diffusion
from responding to short-term fluctuations of the water table. The
interface in zones 4 and 5 has not been accurately determined during
drilling projects so the influence of the clJy unit cannot be
assessed,
The lateral position of the interface is not'in~uenced by the clay.
There is no comparable-barrier to check the horizontal, landward
-encroacrment of' saltwater. Groundwater withdrawals near.the sh~re-
iine, over a prolonged ~eriod of reduced recharge, could have an
effect on the position of_the tnterface with r~spect to-thc shore-~.
line. ~
'(98/13)
SECTION 5.0
GROUNDWATER QUALITY
The groundwater aquifers underlying the North Fork are significantly
contaminated by inorganic and organic chemicals. The nature and
extent of groundwater contamination was evaluated in this study
relative to its impact on water supply. The data used in the analy-
sis was collected by the Suffolk County Depar~ent of Health Services
(SCDHS) in their home- and monitoring-well sampling programs and
their North Fork transect project.
5.1 INORGANIC PARAMETERS
Table 5-1 summarizes the SCDHS data for inorganic parameters an the
North Fork. The table characterizes groundwater quality by present-
ing the percentage of well samples which exceed established guide-
lines or standards for nine inorganic.parameters. Data is presented
for 14 communities on the North Fork (grouped by zone) and for Suf-
folk County as a whole.
Using the data on Table 5-1 and other supporting data from the SCDHS,
it was determined that the upper glacial aquifer throughout the plan-
ning area is already contaminated with nitrates. Nitrate levels are
significantly elevated above natural background conditions of 0.1 to
1.0 milligrams per liter (mg/1) and exceed the drinking water stan-
dard of 10 mg/1 in many areas. A sampling pf 639 wells for nitrates
by the SCDHS in the Town of Riverhead showed the following: 58 per-
cent of the. samples ranged from 0 to 5 mg/1; 26 perce~t were above
7.5 mg/1; and 16 percent were above lO mg/1. Similar results were
obtained in a sampling of 1,121 wells in the Town of Southold: 5t
percent of samples ranged from 0 to 5 mg/1; 30 percent we.re above 7..5
mg/1; and 17 percent were above 10 mg/1.
Figure 5-1 graphically depicts the areal extent of nitrate contamina-
tion in the upper glacial aquifer. As expected, the affected areas
are closely related to 9gricultural land use in zones 1, 2, 3, and-5.
~he vertical ektent of the contamination is also important in pro-
jecting future migration rates through the aduifer system and future
water supply impacts. Themos~ detailed study of vertical conce~tral
tion gradients was done by SCDHS as part of their New York State De-
partment of Health (NYSDOH) pesticide grant. The results of the ver-
tical groundwater quality profiles compiled along a transect in
Cutchogue (Zone 3) showeU extensive distribution of nitrates verti-
]
J
4
'~I
INSERT FIGURE 5-1
cally, permeating almost all of the upper glacial aquifer above the
clay. These results were confirmed by limited vertical profiling at
two other study sites also in Zone 3. The vertical nitrate concen-
tration data from Zone 3 is consistent with groundwater quality find-
ings in other supply zones.
In zones 1 and 2, the fresh water which is available beneath the clay
unit is not contaminated with nitrate and will probably remain un-
contaminated because of the reduced rate of migration of contaminants
through the clay. While only a small number of wells currently tap
the Magothy aquifer, this formation beneath zones 1 and 2 has been
shown to have acceptable water quality and low nitrate concentra-
tions. Samples from Riverhead and Baiting Hollow Magothy wells had
nitrate concentrations of less than 0.02 mg/1. A nitrate concentra-
tion of 1.09 mg/1 was found in a Magothy well in Aquebogue in 1969;
the most recent data from that well {December 1981) showed a small
increase to 2.9 mg/1.
As indicated in Table 5-1, a significant number of samples exceeded
the 20 mg/1 sodium guidelines contained in the New York State drink-
ing water standards. The sodium standard is relevant to consumers on
severly restricted salt diets. The State guideline also indicates
that water containing more than 2?0 mg/1~ of sodium should not be used
for drinking by those on moderately restricted sodium diets. As in-
dicated in the table, few samples approach this level.
Iron and manganese are frequently found in levels that exceed State
standards. These constituents occur naturally in the groundwater and
their distribution on the North Fork is not related to land use acti-
vities. These standards do not represent toxic or hazardous levels,
but have been established for aesthetic reasons {staining of bathroom
fixtures and clothes during washing).
The chloride levels found by the SCDHS in the North Fork transect
were higher than normal background levels (20 mg/1) but well below
the drinking water standard of 250 mg/l~ The elevated chloride
levels correlate with elevated nitrate levels, suggesting that
agricultural fertilizers are the major source of the contamination.
Table 5-1 indicates that the chloride standard is normally not ex-
ceeded in home water supply wells on the North-ForK.
MBAS {detergents)-and sulfates are rarely found in North Fork water
supplies in concentrations exceeding standards. Copper and zinc wer~
similarly not detected in concentrations exceeding established stan-
da6ds.
5-5
5.2 ORGANIC PARAMETERS
Table 5-2 presents the results of the SCDHS home well sampling pro-
gram for the pesticide Aldicarb and three chlorinated hydrocarbons.
This data summarizes the results of the Department's surveillance
efforts which were begun in mid-1979.
The extent of Aldicarb contamination is similar to the distribution
of nitrates because both have been used extensively by potato farmers
on the North Fork. Figure 5-2 maps the areal extent of Aldicarb con-
tamination on the North Fork. SCDHS correlated the presence of
Aldicarb contamination with potato farming; 98 percent of the wells
with more than 7 parts per billion {ppb) of Aldicarb were within
1,000 feet of a potato farm.
SCDHS data and their statistical summaries of Aldicarb sampling re-
sults further demonstrate that organic contamination from pesticides
and herbicides is widespread. In the Town of Riverhead, 2,161 wells
were sampled: 32 percent were contaminated by Aldicarb; and 16 per-
cent had Aldicarb concentrations above the health guideline of 7 ppb.
In the Town of Southold, 3,160 wells were sampled: 23 percent showed
Aldicarb contamination; 11 percent exceeded the health guideline of
7 ppb.
Unlike nitrates, Aldicarb has been shown to be generally limited to
the upper 30 to 40 feet of the aquifer, except in the central re-
charge areas where it has been detected near the bottom of the aqui-
fer. The eventual migration of Aldicarb throughout the aquifer can
reasonably be expected in the future. Efforts to deepen wells to
avoid current Aldicarb contamination will, therefore, provide only
temporary relief.
Most notable among the wells contaminated with Aldicarb are the
Greenport Water District wells 6-1 and 6-2. The water derived from
well 6-1 was found to consistently exceed the ?-ppb guideline while
the water from well 6-2 periodically exceeds the guideline. A carbon
filter was installed in August, t980 to treat the contaminated water
from well 6-1. Water from well 6-2 is blended with treated water
from well 6-1. Additionally, wells 4-6, 4-7, welt 7 and well 8 have
been impacted by pesticide contamination.
SCDHS has sampled for and confirmed the presence of other pesticides
and herbicides in the groundwater beneath the North Fork {dichloro-
propane, carbofuran, dacthal, oxamyl and dinosebl) The data avail-
able on these contaminants is not as comprehensive as that compiled
for Aldicarb but does verify that additional contamination has oc-
curred.
Table 5-2 also presents the results of the SCDHS home well sampling
program for three chlorinated hydrocarbons (1,t,1 trichloroetnane,
tetrachloroethytene, and 1,1,2 trichloroethylene). The use of these
- 5-6
INSERT FIGURE 5-2
5-8
chemicals is generally not associated with agricultural activities.
The greatest occurrence of these compounds was in Greenport, an area
where agricultural activity is limited. The sources of this type of
contamination are generally commercial activities and homeowner use
of the compounds.
After reviewing the water quality conditions on the North Fork, it
was determined that a conservative approach to water supply planning
must be taken because of degraded water quality and the need to pro-
tect consumers. It is clear that the aquifers will remain contamin-
ated with nitrates, Aldicarb and with other organic parameters
through the year 2000. Even though additional inputs have ceased,
concentrations of Aldicarb will continue to exceed the 7-ppb drinking
water guideline. As additional water quality data is collected, more
contamination problems will be discovered.
(98/14)
5-9
]
]
SECTION 6.O
EXISTING WATER SUPPLY SYSTEMS
Within the study area, there are two municipal water supply systems:
one serving the hamlet of Riverhead, and the other, the Village of
Greenport. In addition, there are numerous (21) small, privately
owned water systems. The Riverhead and Greenport service areas and
the locations of the 21 private systems are shown on Figure 6-i.
6.1 GREENPORT MUNICIPAL SYSTEM
The Greenport system presently serves the Village of Greenport and
portions of the Town of Southold, as shown on Figure 6-1. The
franchised area encompasses about 15 square miles extending generally
from East Marion, west to Horton Neck and Jockey Creek. The system
includes about 50 miles of piping serving about 2,300 connections and
has one distribution system storage tank with a capacity of 300,000
gallons.
The Village presently owns and operates six well fields with two
(Plants 1 and 2) abandoned several years ago due to water quality
problems. Table 6-1 summarizes information on the well supplies.
Presently, Plant 3 is only used for emergency purposes due to re-
latively poor water quality. Also, it has been reported that the
yield of Plant ¢ has been reduced to 300 gallons per minute {gpm) due
to the recent activation of Plant 8, since these well supplies are
relatively close to each other and hydrologically connected. There-
fore, the net available pumping capacity is about 1,710 gpm.
At Plant 6, a granular activated carbon filter was installed on the
larger of the two wells during the summer of 1980 (well no. 6-1) in
order to remove pesticides. Union Carbide, the manufacturer of
Aldicarb, supplied the filter and the initial 20,000 pounds of
carbon. Because of the hydraulic restrictions imposed by the filter,
the well capacity was-reduced from 550 gpm to 400 gpm. Water from
this well is blended with water from well no. 6-2 (150-gpm capacity)
resulting in a total combined plant capacity of 550 gpm. Plant 6
represents the major source' of water for the system, accounting for
up to 61 percent of the total water pumped over the last few years.
Aldicarb contamination has also been detected, in lesser degrees, in
the water from wells 4-6, 4-7~ Plant 7 and Plant 8.
6-1
INSERT FIGURE 6-1
6-2
P1 ant
No.
3
4
5
6
8
TOTALS
No. of
Wel 1 s
3
3
1
2
1
1
11
TABLE 6-1
SUMMARY OF WELL SUPPLIES
FOR THE GREENPORT MUNICIPAL SYSTEM
Total Pump Well Historical Water
Capacity (gpm) Depth (ft) Quality Problems
340 45-57 Iron, manganese,
chlorides, pesticides
510 79-80 Occasionally high
chlorides, pesticides
160 60 Nitrates
550 77, 94 Nitrates,
pesticides
350 89 Chlorides, pesticides
350 '95 Pesticides
2,260
5-3
:J
:J
J
If, due to mechanical failure or maintenance, the carbon filter is
inoperable at well no. 6-t, this supply would be removed from service,
reducing the total system capacity from 1,7!0 gpm to 1,310 gpm. This
latter capacity should be adopted for water supply planning purposes
in order to assess future requirements. Accordingly, based on an
estimated maximum day requirement of 1,780 gpm (see Section $.0) it is
estimated that a deficit of about 470 gpm 10.68 mgd) in dependable
water supply capacity will exist by the year 2000.
The Greenport system is well maintained and operated. Its major
problems are the quality of its raw water supplies. However, the
personnel operating the system have been able to cope with the quality
probl~n because of their experience and expertise.
6.2 RIVERHEAD MUNICIPAL SYSTEM
As shown on Figure 6-1, the Riverhead Municipal System (Riverhead
Water District) serves an area north of the Peconic River between
Calverton and Aquebogue. The system presently has about 53 miles of
piping and provides service to 2,124 residential, 346 commercial and
57 institutional customers. Present population served includes 9,900
within the District and 2,200 outside Of the District (Riverside Water
District) for a total served population of 12,100. There are twp
elevated water storage tanks within the system; one having 750,000
gallons of active storage and the other 150,000 gallons. The larger
tank automatically controls the operation of five of the District's
six well pumping stations by use of a telemetering system that serves
to sequentially start or stop the District's pumping stations
according to the water level in the tank.
The District presently has six well supplies; their capacities and
depths are summarized in Table 6-2.
Well no. 2, which is not automatically controlled by tank water
level, is used for emergency purposes,-and is powered by a diesel
engine. Excluding this well, the total net available system pumping
capacity is 5,150 gpm or 7.4 million gallons per day (mgd). Based on
the estimated year 2000 maximum daily demand of 2900 gpm for River-
head, it is apparent that sufficient well caI~acity exists to satisfy
future requirements. Reportedly, there have been no significant
water quality problems or concerns at the well supplies. Chlorine
for disinfection and li~e'for pH control are added at each well,
except for well no. 2 where only ch!orine is added.
6-4
Wel 1
1
2
3
4-t
4-2
5
TOTAL
TABLE 6-2
SUiV~IARY OF WELL SUPPLIES
FOR THE RIVERHEAD WATER DISTRICT
P~mp Capacity (gpm)
75O
800
1,000
1,000
1,200
1,200
,5,950
6-5
Well Depth (ft)
120
140
120
715
390
250
J
1
.~l
The system appears to be well maintained and efficiently operated.
It is essentially IOQ percent metered, with a meter replacement pro-
gram recently being completed. Leakage detection and repair is an
ongoing practice, as is hydrant and valve maintenance. These prac-
tices are the major reason why the unaccounted-for water portion of
the total average daily production is below 10 percent, a relatively
low amount and representative of a well-maintained system.
6.3 PRIVATE WATER SYSTEMS
Excluding the Riverhead and Greenport water districts, 21 privately
owned water supplies were identified as serving residential areas in
the towns of Riverhead and Southold. In all, an estimated population
of approximately 5,¢00 is served by these systems.
Under New York State Law (State Sanitary Code Pt. 5-1.1) these sys-
tems are classified as community or noncommunity systems based on the
number of service connections or seasonal nature of the service.
Those designated as community systems are required to meet more
stringent monitoring and quality requirements.
Several of these water systems have experienced problems related to
lack of standby power, water quality deterioration, and inadequate
pressure. Since these difficulties may directly impact upon the
availability and/or suitability of water, the Drinking Water Supply
Section of the Suffolk County Department of Health Services has de-
signated some of these systems as Marginal Water Suppliers (July
1981). Community water systems serving moPile home parks (M.H.P.),
adult homes and apartments were excluded from this classification
under the assumption that these facilities could be evacuated in the
event of an emergency.
Table 6-3 summarizes the water supply equipment, populations ser-
viced, and classifications of each of the private supplies on the
North Fork. Comments have been included describing the reasons for
"marginal supply" classification, as appropriate.
SPH12/9)
6-6
t
!
X X
X X X
X X X X X
X X X X X
X X X X X
X
SECTION 7.0
WATER USE AND AVAILABLE SUPPLY
7.1 EXISTING AND FUTURE WATER USE
Water use patterns were analyzed for residential use lincluding
commercial and industrial), and agricultural use.
7.1.1 Residential Use
Water for residential use is supplied through both public water sup-
ply systems and individual home wells. The major municipal public
supplies are the Riverhead and Greenport water districts. In addi-
tion to the two major municipal systems, there are a n~ber of
smaller systems serving residential developments and mobile home
parks in the study area.
ODerating records from Riverhead and'Greenport were reviewed to
determine water use in the two districts. The results of the analy-
sis, shown in Table 7-1, indicate that the Greenport District uses an
average of Q.81 million gallons per day (mgd) or 110 gallons per
capita per day (gpcd). The Riverhead District supplies 1.18 mgd or
120 gpcd to consumers in the study area and an average of 0.32 mgd to
the Riverside section of Southampton.
Average daily per capita usage was also examined during the periods
from January to April and October to December. Usage during, these
periods more. accurately rejects domestic use by permanent residents.
Both the Riverhead and the Greenport_systems reflected per capita use
of 90 gpcd during these months.
The relationship between annual average daily use and peak seasonal,
monthly and daily demands were evaluated in_both systems and found to
be almost identical. Average dai~y use during the peak season (M~y
to Sept~ber) is 1.25 times annual average daily use. The peak month
for consumptien is July and average daily.use during that month is
1.6 times the annual average. The peak dai-ly demand experienced was
-2.7 times the-annual average daily use.
Residential use in a~eas not served by a publio supply ~as-estimated
to be 80 gpcd. The lo,er-per Capita rate in these areas (80 versu~-
110 and 120 gpcd) results from two factors:
charged to the ground (i.e., discharged to a sewer system with sur-
face water outfalls}. Therefore, all agricultural use is considered
as consumptive use (leaving the system as evapotranspiration). Re-
sidential use in sewered areas was assumed to be 100 percent con-
sumptive, while residential use in unsewered areas was estimated to
be 20 percent consumptive. Table 7-2 lists existing and future con-
sumptive use figures for each zone. As with total use, consumptive
use will decrease in the future as irrigation requirements decline.
Peak water use rates were developed by applying the previously deter-
mined peak use factors to the future annual average daily use rates.
During summer months, domestic use will be over 6 mgd; agricultural
use will be about 22 mgd.
7.2 AVAILABLE GROUNDWATER SUPPLY
Groundwater reaches the aquifers underlying the North Fork from two
sources: (1) annual recharge from precipitation and (2) groundwater
in.ow from outside the study area. Of these two sources, annual
recharge provides the majority of water reaching zones 1 and 2, and
essentially all of the water in zones 3, 4 and 5. Groundwater inflow
from Brookhaven Township to zones 1 and 2 is estimated at 7 mgd
{CPWS-24, 1970). The aquifers underlying zones 3, 4 and 5 are iso-
lated and do not receive in.ow from other groundwater sources.
Average annual recharge is estimated to range between 19 and 21
inches per year or 42 to 46 percent of the total average preci-
pitation (45 inches per year). The average recharge of 19 to 21
inches is equivalent to approximately 1 mgd per square mile of land
area. In reality, however, not all of the recharge should be
withdrawn for use. Some recharge must be allowed to ~ow across the
fresh water-saltwater interface to prevent the movement of the inter-
face and sal.twater intrusion.
CPWS-24 contains the following permissive sustained yields for the
groundwater supply zones on the North Fork:
Groundwater
Supply Zone
Permissive Sustained
-Yield (mgd/sb mile)
1 0;7 '
2 0.4
3 0.35
4 0.25
5 0.25
The permissive sustained yield is the maxim:n rate at which water
may be withdrawn from the aquifer perennially without bringing about
the undesirable effects of saltwater intrusion. The permissive
~
j-
sustained yields were ~eveloped during the preparation of CPWS-24
through an optimization procedure that balanced maximum withdrawal
with storage capacity in each zone, Since groundwater elevations and
aquifer storage volumes in zones 3, 4 and 5 are lower than in zones 1
and 2, the permissive sustained yields for these eastern zones were
developed utilizing recharge rates reflecting drought conditions
rather than the average recharge rates used for zones 1 and 2.
The permissive sustained yields for each zone were examined in this
study. Using the most recent data and information available, the
impacts they would have on the position of the saltwater interface
were estimated. It was found that these yields would have only a
minor impact on the configuration of the fresh water-saltwater inter-
face.
In order to estimate the total quantity of groundwater that may be
withdrawn for public supply from each zone, water budget areas were
delineated {see Figure 7-1). The budget areas represent those loca-
tions where there is sufficient groundwater to develop large public
supply wells. Outside the budget area, there is only sufficient
supply to allow the development of smaller home well systems.
In zones i and 2, the budget areas were defined as those locations
where the groundwater level is 5 feet or more above sea level. In
zones 3, 4 and 5 the availability of groundwater is more limited;
therefore, the budget areas in these zones were defined as the areas
where the groundwater level is 2 feet or more above sea level.
Allowable withdrawal rates and well capacities will be more limited
in the three eastern zones because of the lower groundwater elevat-
ion. The definitions of the water budget areas are consistent with
those presented in CPWS-24.
Table 7-4 presents summary data for the water budget areas in each
groundwater supply zone. As one progresses west to east through the
study area, the size of the water budget area generally decreases.
Zone 1 has a water budget area of 42 squaPe miles (approximately 95
percent of the total land area). In Zone 5, the budge{ area covens
1.6 square miles, 'representing only one-third of the total land area.
These areas were based upon interpretation of the March 1981'ground-
water contour map prepared by the SCDHS.
Total permissive sustained yields were derived by app)ying the unit-'
yield rates listed above {mgd per square mile) to the area covered Qy
the water budget areas. The total permissive ~ustained yields range
from a high of 29.4 mgd in Zone 1 to a low of 0.4 mgd in Zone 5. It
should be emphasized that these total permissive susiained yields
only account for the q~antity of water that may be withdrawn from the
water budget areas. AdditiQnal groundwater suppl~ may be'oDCained- ..
from smaller capacity, private home wells located outside the budget
areas. It is estimated that approximately 10 to 20 mgd could be
available outside the water buUget areas for all five zones.
J
j-
7.3 WATER BALANCES
Table 7-4 compares the quantity of available groundwater with current
consumptive water use in each zone. Each of the zones {excep~ Zone
5) potentially has sufficient quantities of water to meet anticipated
demands without causing adverse impacts from saltwater intrusion.
Zone I has the largest surplus of water available (2¢.7 mgd); zones
2, 3 and 4 have a more modest surplus. In Zone 5, the analysis indi-
cates that the current consumptive use is approximately equal to the
permissive sustained yield. Again, it should be emphasized that
there is additional water available for use in Zone 5 outside the
water budget area. that can be developed utilizing small capacity
wells.
In reviewing the findings of the water budget analysis, several
important factors must be considered:
(1)
Well location and design require special attention in ground-
water supply zones 2, 3, ¢, and 5 because of the low per-
missive sustained yields and shallow aquifers.
~n the
rained
future
Because of pesticide and nitrate contamination, all fresh
groundwater potentially available may not be suitable for pot-
able water supply without treatment, but could be used for
irrigation.
development of water supply, alternatives, the permissive sus-
yields and the quantity of water potentially available for
use were utilized to identify possible sources of supply.
7.4 WELL YIELDS AND SPACING CONSIDERATIONS
The permissive sustained yields presented earlier represent average
withdrawal rates that are appiicable acros~ an entire groundwater
supply zone. Individual well capacities and well spacing must also
be considered when developing specifi~ water supply alternatives.
7.4.1 Well Yields
The yield that can be obtained frQm a well i~ dependent upon a number
of inter~elated factors:
7-9
J
]
I
Specific capacity of the aquifer
Height of the water table above sea level
Proximity to saltwater bodies
Well screen location and length
Well finishing and development techniques.
While specific information can best be obtained from site investi-
gations and pump tests, sufficient information currently exists to
make planning decisions on well spacing, location and yields.
The Suffolk County Test Well Program and data developed by the USGS
indicate that the specific capacity for wells in the upper glacial
aquifer averages 30 gallons per minute per foot (gpm/ft) of drawdown.
(See Section 4.2 for a complete discussion of aquifer parameters.)
This means that properly constructed wells can generally yield 30 gpm
for each foot the water level in the well drops after pumping com-
mences. Water table wells located close to saltwater bodies should
not be designed and operated in such a manner that the continuous,
average drawdown level over the year is below sea level, as t~is will
induce saltwater intrusion into the well.
As a general rule, wells are designed to meet peak day requirements
{generally two to- three times annual average pumping rates). There-
fore, the well only pumps about 5D percent of the time to meet the
annual average demands. It is, therefore, permissible to design a
water table well so that it will have an intermittent pumping level
below sea level, realizing that during the inactive pumping periods
the well will recover. It is typically assumed that if a well is
located several thousand feet from a saltwater body, it can be
designed to have a drawdown twice the height of the static water
level above sea level, and still operate safely without drawing
saltwater from lateral or upconing intrusion. Such a well should not
be pumped continuously; it should be used only 50 percent of the time
and allowed to recover the other 50 percent of the time.
Allowable well capacity can then be calculated: (1) if the height of
the water table is known, (2) assuming a 30 gpm/ft specific capacity,
and (3) all owing a total drawdown of two times the static water level
above sea level. In zones I and 2, the water table ranges from 5 to
40 feet above se~ level. Wells in the water budget areas within
these zones c'an, therefore, be designed to provide 300 gpm to over
1~000 gpm. In the water budget areas in zones 3, 4 and 5, the hedght
of-the water table ranges from 2 to 4 feet above sea level. Wells in
these zones can be designed for capacities of 120-to 240 gpm._
7-t0
The larger seasonal and weekend increases in the water supply re-
quirements of the North Fork further complicate the design of wells.
If the well-sizing criteria discussed above were followed, a large
number of small-capacity wells would be required to meet peak weekend
summer demands. Many of those wells would be completely inactive
during the week and the off-peak season. This type of well network,
comprised of numerous small wells, would be prohibitively expensive
to construct and operate. It was, therefore, decided to allow peak-
ing wells to pump intermittently at drawdowns up to 3 to 4 times
greater than the static water level above sea level. The larger
wells would only be operated on peak weekends during the summer.
Since their period of operation will be limited, there would be no
danger of drawing saltwater into the well.
The well yields and negative saltwater impacts predicted through this
type of analysis were verified by examining the existing installed
capacities and saltwater impacts of the Greenport Water District
wells. {The Riverhead Water District wells tap the Magothy aquifers
in Zone 1 and are not subject to saltwater intrusion and, therefore,
could not be used to further verify the assumptions.) The Greenport
wells range in capacity from 200 to 400 gpm. The smaller capacity
Greenport wells produce yields which are consistent with those pre-
dicted by the assumptions made in this study with no saltwater intru-
sion proDlems. The 400-gpm wells, however, are larger than would be
allowed by the specific capacity/drawdown criteria of thi~ study
{drawdowns greater than twice the height of the static water level
above sea level). A review of the Greenport records indicates that
their larger wells must be periodically rested because of increasing
high chloride concentrations. In essence, then, the larger wells are
sized and function similarly to the peaking wells assumed in this
study, and substantiate the assumption that larger wells can be used
on an intermittent basis to satisfy peak summer weekend requirements,
if carefully monitored and controlled.
Although the well-yield analysis has been presented for the water
budget areas in each zone, the same general analytical approach can
be used for locations outside the budget area. In summary then,
wells tapping the upper glacial aquifer can be pumped intermittently
at the following capacities without drawing saltwater:
Height of Water Table
Above Sea Level
(feet)
Capacity
(~pm)
5 300
4 240
3 180
2 60-120
1-i/2 45-90(1)
1 15-30(1)
Less than 1 0-10(1)
(1) Requires site specific investigations and analyses.
]
7.4.2 Well Spacin?
Wells should be located and spaced based upon considerations of the
effective radius of influence of each well. A well should not be
located closer to a saltwater body than a ~istance equal to two times
its effective-radius of influence. Furthermore, wells within a group
should be separated by a minimum of two radii of influence (center-
to-center) so that their areas of influence do not overlap. These
spacing criteria were used in subsequent phases of this investiga-
tion.
?or steady-state conditions, the radius of influence of a pumping
well describes an area over which the recharge rate is equal to the
well pumping rate. This relationship is described by the following
equation:
QW= '~ro2 w
where, QW: effective well pumping rase in gallons/minute
ro = radius of influence in feet
W : recharge rate in gallons per squ~re foot per minute
(18 inches per year : 2.13 x 10- gallons per square
foot per minute)
To normalize the p~ping rate over the year, QW was taken to be edual
to the total annual 'quantity of water withdrawn from the welt distri-
buted evenly over the entire year {effective well pumping rate).
Using the effective pumping rate and'~n average recharge of 18
inches/year, ro was calculated and used to define minimum well spac-
ing distances, as described above.
Example. As an example of the well-yield analysis and the use of the
above equation for well spacing, assume that a total well capacity of
900 gpm was required to satisfy a peak day requirement for a particu-
lar service area where the groundwater table was 5 feet above sea
level. Three wells would be required, each with a capacity of 300
gpm, based on a specific capacity of 30 gpm/foot and allowing eac~
well to draw down to a level twice the static level above sea level
(2 x 5 feet = 10 feet). Using a recharge rate, W, of 18 inches/
year and QW equal to 300gpm, r was calculated to be 2,050 feet.
These wells were then located ~,100 feet apart.
Groundwater Technology, David K. Todd, 1964.
(125/i1}
7-12
SECTION 8.0
WATER SUPPLY ALTER~,~IVES
8.1 WATER DEMAND CENTERS
The initial step in developing and analyzing water supply alterna-
tives was to define the location and magnitude of water requirements.
Accordingly, water demand centers which represent the greatest con-
centrations of population and/or commercial development within the
study area were delineated. As shown on Figure 8-1, five m~or
demand centers were identified. Within each demand center, subdemand
centers were al so delineated; these represent the m~or concentra-
tions of population within the larger demand centers. The future
land use plan, as projected by the Long Island Regional Planning
Board (LIRPB) during the 208 Program, was utilized to estimate the
extent of future development and, accordingly, subdemand center
boundaries. Separating each demand center into subdemand centers was
primarily done for water supply planning purposes because it facili-
tated development and analysis of a more localized level of altern-
atives for comparison with larger subregional or regional options.
Nine isolated neighborhoods that represent concentrations of popu-
lation removed from the demand centers were also identified (see
Table 8-1). They generally consist of single-family homes built as
part of a subdivision, with each home having an individual well sup-
ply. These neighborhoods were identified in order to develop and
analyze water supply options that would be available at a smaller,
neighborhood scale. The homes within these neighborhoods have wells
that withdraw water from the upper glacial aquifer, which is, or has
the potential to be, laden with objec%ional concentrations of
nitrates and/or pesticides.
Table 8-1 summarizes the estimated year 2000 populations and water
consumption requirements for each subdemand center and isolated
neighborhood. Future population was estimated, as discussed in Sec-
tion 3.0, with detailed census tract data and LIRPB estimates uti-
lized to apportion population among demand centers. Future water
consumption was estimated by the methods presented in Section 7.0.
Generally, historical water use trends were utilized to develop the
following estimates of water consumption given in gallons per capita
per day (gpcd):
8-1
]
J
J
d
INSERT FIGURE 8-1
8ST?ATED Y~ 2000 P0PULATION
~ERMAN£NT AOD'L SU,'~4ER TOTAL
AVE DAY ~X DAY PEAK HOUR
Waoinq River/Nort~ville
120 165 210
660 1780 2500
860
100 200 295
3985
(5.74 MGO)
20 45 70
8 17 26
27 60 90
8 17 26
13 28 43
10 21 32
6 13 20
18 40 62
23 50 80
4118
(E.g3 ~r~)
80 gpcd
Residential use in areas not presently served by
public supply
t10 gpcd - Greenport Municipal System permanent residents
120 gpcd - Riverhead Municipal System permanent residents
50 gpcd
Summer residents.
The above rates were used to estimate year 2000 average daily water
use. Maximum daily water use, which is used to determine the design
capacity of most waterworks facilities, was estimated using a maximum
day to average day ratio (i.e., maximum day ratio) of 2.5, based on
historical water use trends for the Greenport and Riverhead municipal
systems. The maximum day use represents the largest 24-hour water
use that is expected to occur within a year, usually during the sum-
mer season when water use is higher. The maximum day ratio was
applied only to the average daily water use for permanent residents,
since summer residents would, most likely, use water at a more con-
stant rate throughout the season, with lawn watering and car washing
being less prevalent within this class of users. The adopted rate of
50 gpcd for summer population is, most probably, slightly conserv-
ative and should be more than adequate to account for any fluctua-
tions in average daily water use.
Peak hourly water use was estimated using the same method that was
established for maximum day use, but using a peak hour ratio of 4.0.
Peak hour represents the largest water use expected to occur over a
1-hour period during the maximum day {i.e., the highest hourly flow
expected to occur within a year), and was used in this study :o size
pumping facilities for systems that do not have available system
storage.
8.2 WATER SUPPLY CONCEPTS
Based on the present groundwater quality problems associated with the
upper glacial aquifer, as discussed earlier in this report, the need
for water supply planning is apparent. According to historical area
groundwater quality data and the resulting mapping that was developed
to show the extent of nitrate and pesticide contamination, it is evi-
dent that most individual home well systems throughout the study area
presently have, or in the future, may have objectional levels of
nitrates and/or pesticides. The Greenport Municipal System has ex-
perienced high levels of nitrates and pesticides, in addition to
iron, manganese and chlorides. Additional water supply is also re-
quired in Greenport. The Riverhead system has an adequate, high-
quality supply primarily due to the utilization of water from the
Magothy aquifer. Accordi_ngly, water supply planning, from a quality
and quantity standpoint, is not required for this system. However,
recommendations associated with distribution system storage and con-
tinuation of the present operation and maintenance practices will be
addressed later in this report.
8-4
In order to evaluate all available options that would provide ample
and high-quality water to North Fork residents, several water supply
concepts were developed. These essentially represent a building
block approach ranging from individual home well treatment systems
large-scale regional systems. Five levels of water supply alterna-
tives were developed and evaluated:
TABLE 8-2
WATER SUPPLY CONCEPTS
Level I:
Level II:
Level III:
Level IV:
Level V:
Individual Home Water Supply Systems
Neighborhood Systems
Subdemand Center ("Community") Systems
Subregional Systems
Regional Systems
8.2.1 Level I Alternatives
Several Level I alternatives were developed and .evaluated:
- Home treatment units
Bottled water
Local delivery of bulk water
- Local supply of bulk water (with treatment).
8.2.1.1 Home Treatment Units. Reverse osmosis (R-O) was chosen as
the preferred met~oO of treatment in individual home systems (see
Section 8.3). Two basic concepts werb developed for individual'
homes:
- Treatment of the entire home supply
'- Treatment of drinking/cooking supply only (kitchen tap).
Although they are not commonly used, individual R-O systems compact
enough to install in a home are available to produce up to 400 gal-
lons per day (gpd) of treated water. These uni.ts are typically in- -
stalled in commercial establishments. For a'domestic installation,
water supplied from a contaminated home well would be.piped to the
R-bunit. A booster-pump .would be used to raise t~e water pressure
to approximately 200 pounds per square inch gage (psig), the~inima!
working pressure of the unit~ Treated water, or permeate, would pass-
through a pressure-reducing valve to a 50- to lO0-galton storage tank
maintained at 60 psig. Concentrated reject water, or brine, would be
disposed of in a small dry well for percolation into the ground.
This will not exacerOate groundwater contamination.
8-5
Trea~ent of only the drinking/cooking supply would require the in-
stallation of a compact under-sink unit. These units are capable of
treating 5 to 20 gallons a day. In an installation of this type,
water would be supplied to the entire home through an individual home
well. The R-O unit, installed under the kitchen sink, would be tap-
ped into the cold water supply line. Normal house pressure (30 to 50
psig) can operate these units with no booster pump required. The
treated water is stored in a small hydropneumatic tank, which is con-
nected to a third faucet. Reject water is piped directly to the kit-
chen sink drain line for disposal. The unit will be serviced every
six months to replace filters, clean the membrane, and collect
quality control samples.
8.2.1.2 Bottled Water. As an alternative to home treatment units, a
home supply can be augmented by periodic delivery of bottled water.
It was assumed that the daily consumption of bottled water (for
drinking and cooking purposes) would be limited to i gallon per day
(gpd) per person. A1 though average levels for individual consumption
are typically much higher, the high cost and restricted availability
of bottled, as opposed to tap, water was assumed to restrict consump-
tion. Bottled water would be delivered once or twice a week in re-
turnable, plastic containers of 5-gallon capacity. A deposit would
be required on each bottle delivered to ensure return of the con-
tainers. A bottle stand, rented monthly from the water supplier,
would dispense the water.
8.2.1.3 Local Delivery of Bulk Water. For this concept, a 5,000-
gallon tanker truck would be empl6yed to deliver water purchased from
the Riverhead water supply system. The tanker would be driven to a
central community station, where it would remain until depleted. At
that time, it would be replaced with a full tanker and towed to
Riverhead for refilling. Residents would be required to transport
their own water. It was assumed that the 5,000-g~llon tanker would
be replaced once a week, each household would make 120 roundtrips {at
6 miles) per year, and the community station would be located within
35 miles of the Riverhead Water District. Each station would serve
approximately 1,000 people.
8.2.1.& Local Supply of Bulk Water (With Treatment). In areas of
groundwater contami'nation', t~e alternative Qf providing a treated
supply of bulk water at a central source-was investigated. A central
supply of groundwater would be treated to remove nitrates and pesti-
cides, and stored in a supply tank for distribution'. As above, the
residents would be required to pick up their water' for drinking and
cooking purposes. Each ~tation would also serve about 1,~O0 people.
8.2.1.5 Individual Home Wells. It is important to ndte that in ~)l
Level I water-suPply concepts,_ even those which require the-importa-
tion of potable water, an individual home well system is required for
each residence. For existing homes in areas of contami-nation, the
well system would continue to be required either as a source of non-
potable water and/or to supply an inOividual treatmen: system. Each
well system would consist of t~e'following major combonents:
8-6
Well casing and screen
Pump and motor
Storage/pressure tank
Piping and valving
Electrical equipment and controls.
Well systems in different areas of the North Fork have different well
requirements. In Wading River, for example, a 200-foot well depth is
typical, requiring a 4-inch casing and a submersible pump. In River-
head, depth to water averages 100 feet and a 2-inch casing with a jet
pump is adequate. Southold Township wells average 75 feet in depth;
a 2-inch casing with a jet pump is also adequate for these installa-
tions.
Typically, the service life of a 4-inch well is about twenty years: a
2-inch well system would require replacement every 10 years. For
comparative purposes, it was assumed that a 4-inch well system would
require a replacement pump every i0 years, while a 2-inch system
would require a new casing and screen to be driven and the pump to be
replaced every 10 years.
8.2.1.6 Level I Cost Estimates. Costs for individual home well sys-
tems were developed by averaging costs for new installations as ob-
tained from local North Fork drillers. For 200-foot-deep, 4-inch
wells typically installed in an area similar to Wading River, a com-
plete installation averages $4,~00, including pump,.pressure/storage
tank and all necessary piping and valves.. Shallower wells, requiring
a 2-inch casing, averaged $1,600 (lO0-foot depth) and $1,200 (?5-foot
depth). Some areas may utilize slightly less expensive suction pumps
in the well system. This should not significantly impact the accura-
cy of the cost analysis. For these new installations, an amortized
cost was developed under the assumption that the capital cos{ would
be included in the cost of the home-and resulting-mortgage loan.
Loan terms of 14 percent for 30 years were used for these calcula-
tions. Additional annual costs include power, routine maintenance
(estimated at $70 a year), insurance, and well replacement. An addi-
tional insurance premium of $25 a year is typically charged for lack
of fire protection in areas ~hich are not served by water systems,
for fire protection. A sinking fund factor was applied (10 percent,
10 years) to annualize the $750 pump replacement cost for ~-inc.h
wells expected every 10 years. An identical factor was applied to
the cost of replacin~ the 2-inch well casing and jet pump (estimated
at 60 percent of first cost) every 10 years.
Costs for existing h6mes-presently served by individiual Jell systems
.were developed by subtracting the amortization of the _capital ~os~
from the to:al annual cost of a new well system.
A summary of annual costs for new and existing homes in areas where
well. supplies do not require treatment is presented in'Table 8-3. A
new home in an area with a depth to water of 200 feet would incur an
annual cos: of $810. For an existing home with a well system, annual
operating costs were estimated to be $155 to 3172.
Home owners in areas requiring treatment of groundwater supplies
(using R-O systems) must incur a~ditional costs t~ pay for the capi-
talization, operation and maintenance of these systems. Under-the-
sink R-O systems treating 8 to 20 gallons a day have an average cabi-
tal cost of $650. Annual operation and maintenance lO&M) costs for
these systems include two service calls for replacement of filters
and membrane cleaning. R-O units capable of serving entire homes
have a capital cost of $1,800 (this figure may be significantly
higher for homes which require additional storage and/or flow capa-
city to meet peak demands). These units also require two service
visits a year. In order to develop an annualized cos~ of individual
systems which include treatment, it was assumed that these units
would be purchased by a central authority that would own and maintain
them. Costs would be passed on to the home owner. Amortized costs
for these units were developed using terms typical to a municipal
bond (12 percent, 40 years). Operating costs for these systems were
developed from manufacturers' quotes. The annual O&M cost for an
under-the-sink R-O unit was found to average about $100; the annual
cost to maintain an entire home unit was about $170. For units serv-
ing an entire home, an additional S30 a year is required for power
costs associated with the R-O booster pump.
As can be seen in Table 8-4, a new, complete individual home well
system with treatment, includes the amortized costs of the well sys-
tem and treatment equipment, plus the O&M costs assigned to the R-O
unit and well system. For new homes equipped with under-sink units,
total annual costs ranged from S~05 to $990; using R-O units to treat
the total home supply increased these costs to $745 to $1,230 a year.
For existing homes, the capitalization of the well system can De sub-
tracted. This lowered the range of costs to $335 to $352 a year for
under-sink units and $575 to $592 for entire home units. These costs
also include the O&M associated with the existing well system.
The cost of using bottled water for drinking and cooking supply was
developed using vendor quotes. Presently, water can be purchased for
$1.19 a gallon, with a minimum delivery of five 5-gallon bottles.
Assuming a per capita consumption of 1 gallon a day, annual water
cost per household (average of 3.2 people) would be $1,510, including
$10 a month for rental of a bottle stand. A fully refundable deposit
of $100 would also be required. These costs must be added to those
incurred for individual well systems, which must still be operated to
supply the remaining wa~er demand.
Local delivery of bul~ wa:er to a central location incurs transporta-
tion and operational costs in addition to the cost of the water.
Assuming a 1-gpcd consumption, a 5,000-gallon tanker can serve 1,000
people for about 5 days. ~sing a bulk purchase price of $0.60 per
1,000 gallons for Riverhead water, a tanker cost of $40,000, and an
annual labor cost of S8~,000 per man-year, a total estimateQ annual
cost of $200 per household was calculated. This includes a 15-year
capitalization of the tanker at I2 percent, O&H at S0.40 a mile, and
a 3S-mile round trip for refills. It was also assumed tha~ each
8-9
J
.J
J
.ii
J
J
household would require 120 trips to the tanker per year at an aver-
age round trip of 6 mil es. Auto reimbursement was taken ~o be S2.25
a mile. As above, each household also would be required to maintain
and operate an individual well system.
Treatment of local water, with community pickup as above, would re-
quire a central treatment plant and a storage tank. The cost of a
facility to remove nitrates and pesticides (using ion exchange and
carbon) at a flow rate of 25 gallons per minute (gpm) was estimated
at S97,000. Capitalization of this cost, with associated 0&M costs
and consumer mileage costs, resulted in a per household cost of SB22
year. Again, each household would require an individual well system.
Based upon cost and convenience, individual home treatment units were
selected as the optimum Level I alternative to compare with Level II,
Ill, IV, and V alternatives presented in the following sections.
8.2.2 Level II--Neighborhood Systems
This level of alternatives includes the following:
(i) Providing a new public water supply system for the nine iso-
lated neighborhoods listed on Table 8-1
(2)
Upgrading the existing neighborhood water systems located in
the Wading River/Northville demand center and the Mattituck
West subdemand center.
The required components associated with the development of a new
public water system for isolated neighborhoods include two production
wells, each capable of providing the maximum daily demand. Each in-
stallation would include a submersib)e vertical turbine well pump in-
stalled in a vault. The well pumps would deliver water to a booster
pumping sta%i0n, which would serve to increase system pressures to
desirable limits for distribution to c6nsumers (50 psi to 60 psil
through a piping network. It was assumed that 6-inch-diameter
cement-lined piping would be provided for water distribution. The
booster station would house all controls, chemical addition facili-
ties and standby power. A hydropneumatic tan~ would also be provided.
to assure_ proper system operation a~d control pumping cycles. In
general, the n~ighborhood systems 1 through 5 in Table 8-1 could tap
the Magot~y aquifer, avoiding the need for treatment. The Magotny
aquifer underlying systems 6 through 9 is brackish; thus, it was
assumed that the upper glacial aquifer would be utilized, with
~reatment for nitrates_ and pesticides required.
Upgradi-ng the existing neig~borh'ood water systems would include pro-
viding additional supoly, if required, and providing treatment faci-
lities, since all wells presently tap the upper glacial aquifer.
Supply augmentation was assumed for those systems expected to exper-
ience supply deficits, based on es~imated year 2000 maximin Gay de-
mand. In addition, a minimum of two well supplies was considered a
requisite; thus, a second well was provided for systems having only
one at the present time. It was also assumed that the existing
piping systems are adequate and their continuous use would be main-
tained.
8.2.3 Level III--Subdemand Center Systems
Level III alternatives generally consist of the development of new
public water systems for each subdemand center as illustrated on
Figure 8-2. Under this concept, each system would be a separate
entity and essentially include components similar to those described
for the isolated neighborhood systems, but at a larger scale. Simi-
larly to Level II, treatment was assumed not to be required for those
subdemand centers that could tap the fresh water portion of the
Magothy aquifer. These include the Wading River/Northvitle and
Riverhead/Jemesport demand centers. A1 so, treatment was assumed not
to be required in the Little Hog Neck and New Suffolk subdemand
centers.
Water system components for the subdemand centers within the Wading
River/Northville and Riverhead/jamesport demand centers (excluding
the Riverhead subdemand center) include production wells, well pump-
ing stations, and transmission and distribution piping. Since there
are several existing neighborhood systems located throughout the
Wading River/Northville demand center and an existing system located
in the Mattituck West subdemand center, two Level III options were
developed for these areas, as follows:
Level III (A) - A new public system would serve the presently
unserved areas only.
Existing systems v~uld be upgraded as required
(under Level II alternatives) for continued
operation.
Level III (B) -
A new public system.would serve the presently
unserved areas and provide supply to existing
neighborhood systems.
Existing neighborhood system suoplies would be
discontinued {or used as ~ back-up source), but
existing distribution systems would remain in
service.
T~o Level III options were also developed for augmentation of'the
Greenport Municipal System, which has been designated as a subdemand
center within the Sou:hold/Greenport Uemand center. They are summar-
ized as follows~
8-13
Level III (A) -
Renovation and use of an existing farm well for
municipal supply (9ononue's Farm Well, an agri-
cultural well on County Rt. 48).
Construction of a water treatment facility for
reduction of nitrates, pesticides and dissolved
solids from plants 6 and 7 and the Donohue's
Farm Well.
Additional distribution system storage and
piping.
Level III (B) - Development of a water supply system at Great
Pond.
- Continued use of existing supplies as required.
- Additional distribution system storage and
piping.
The specific alternatives as they apply to each subdemand center
under Level III are described in detail in Section 8.4. Water treat-
ment processes evaluated for this analysis and adopted for cost esti-
mating purposes are discussed in Section 8.3.
8.2.4 Level IV--Subregional Systems
Under this concept, a single puDlic water system would be developed
for each of the five demand centers. System components would include
a central well supply and production facilities (multiple wells),
treatment facilities as required, transmission piping and distribu-
tion pi ping and storage facil'ities. For the Riverhead/Jamesport and
Southold/Greenport demand centers, 'expansion of the existing ~unici-
pal systems 'to serve adjacent subdemand centers wouldPbe analyzed
under this level. The major intent o~ the investigation of this con-
cept was to compare the differences in supply and treatment costs
'between Level IV and 'Level III, since piping costs would essentially
be the same. As will be discussed in Section 8.4, it was found that
detailed consideration of Level IV alternatives was ~ot warranted,
for the_most part, for economic reasons, generally related to distri-
bution system piping requirements and the resulting costs. However,
considerat.ion was given to development of a Water system with central
supply sources for the'Wading River/Northville demand center for com-
-_parison with ~evel III. Supplying'Calverton from the Riverhead Water
District was also evQldated under Level III. Figure 8-3 schemati-
cally depicts the elements associated with t~ese analyses. ~' ..
detailed discussion of these analyses is presented in Section 8.4.
8.2.5 Level V--Regional Systems
Regional systems evaluated for this report generally consist of the
following major components:
CALVERTON
/
DISTRIBUTION
SYSTE~
RIVERHEAD/
AQUEBOGUE
JAHESPORT
RIVERHEAD/JAI1ESPORT DENAND CENTER
L£VEL IV
. cHE:.,A ~ I C OF SUBREG I ONAL S. ~ ~ ~..~
Supply wells plus production facilities from potable ground-
water sources in Riverhead {I.lagothy aquifer)
Transmission system from supply to demand centers
Distribution system piping and storage for demand centers.
The Level V analysis focused only on the Mattituck/Cutchogue and
Southold/Greenport demand centers. Providing a supply from Riverhead
to Wading River/Northville was not considered, since potable ground-
water is available within the demand center itse)f; thus, a more re-
mote supply could only result in a higher cost. Similarly, the
Riverhead/Jamesport demand center was not considered under Level V
since potable water is available from the Riverhead district which
could serve Calverton {Level IV) and Jamesport. Orient was also ex-
cluded from Level V primarily because of the extensive transmission
system piping and pumping requirements and resulting high costs
associated with providing water to this relatively remote area from a
source in Riverhead.
Several alternatives were developed and analyzed under Level V, rang-
ing from augmentation only of the existing Greenport system, to sup-
plying the entire Mattituck/Cutchogue and Southold/Greenport demand
centers. In all cases, the supply sources would consist of new pro-
duction wells in Riverhead. For alternatives involving Greenport,
two scenarios were considered:
(1)
Providing a supply to satisfy the estimated year 2000 maxi-
mum daily demand, and discontinuing the use of Greenpor-'~'~-
existing well supplies (except for emergencies)
(2)
Providing a supply to satisfy the estimated year 2000 aver-
age daily demand, and continuing the use of Greenport's
~-T~l~est quality supply wells to serve as supplemental
sources when required.
The latter scenario is based on the assumption that the quality of
water from the Greenport wells would improve with reduction in
groundwater withdrawal requirements.
A summary of the 'alternatives evaluated under Level V is presented in
Table 8-5.
8.3 WATER TREATMENT PROCESSES
Water treaT~nent for the remJval of nitrates and pesticides is a m~or
component of Level I, II and tli alternatives. Alternative III{A)
for Greenport also includes reduction of total dissolved solids (TDS)
from existing well supplies owing to occasionally high chloride
levels. The following processes were considered for removal of ~nese
constituents:
8-17
TABLE 8-5
LEVEL V ALTERNATIVES
Alternative
Service Area
(D.C. : Demand Center)
(S,D.C. = Sub Demand Center)
V(A)
V(B-i)
V(B-2)
v(c-1)
v(C-2)
¥(o-1)
Mattituck/Cutchogue D.C.
Mattituck/Cutchogue D.C.
Southold/Greenport D.C.
Mattituck/Cutchogue D.C.
Southold/Greenport D.C.(I)
Greenport Municipal System S.D.C.
Greenport Municipal System S.D.C.(1)
Mattituck West & East S.D.C.'s(2)
Greenport Municipal System S.D.C.
MattitucK West & East S.D.C.~$(2)
Greenport Municipal System S.DJC.(1)
Year 2000 Supply
(Max.. Day or Ave. Day)
Max. Day
Max. Day
Max. Day
Max. Day
Ave. Day
Max. Day
Ave. Day
Max. Day
Max. Day
Max. Day
Ave. Day
(1
Alternative includes continuing the use of Greenport's highest quality
well supplies.
Evaluated these S.D.C.'s separately Oue to economic reasons which are
discussed in Section 7.~.
!22/!
Constituent
Treatment Process Considered
Nitrates
Pesticides
TDS
Reverse Osmosis, Ion Exchange
Reverse Osmosis, Carbon Adsorption
Reverse Osmosis
As shown, the process of reverse osmosis is capable of reducing all
of the constituents to acceptable levels. However, based on an
analysis of treatment facility requirements and associated costs, it
was found that removal of nitrates and pesticides could be accomp-
lished at a lower cost utilizing the processes of ion exchange and
carbon adsorption. Accordingly, these unit processes were adopted
for development of water treatment cost estimates for nitrates and
pesticide removal for Level II and III alternatives. For alternative
III(A) (Greenport), TDS reduction is also required. For this alter-
native, the process of reverse osmosis was adopted for cost esti-
mating purposes. The proposed reverse osmosis system is identical to
those used for desalinization of brackish water.
It should be emphasized that the treatment processes considered and
adopted for this study are based on average study area water quality
parameters and reported process Wemoval efficiencies obtained from
historical operating data from existing facilities, manufacturers'
information and literature. They do not re~ect site-specific treat-
ment requirements; these would be determined by water quality analy~
sos and pilot plant testing that is beyond the scope of this study.
However, the treatment costs presented in this report and utilized
for development of alternative costs, sufficiently represent treat-
ment costs in a level of detail comparable to other alternative
components.
A summary of water treatment processes adopted for this study
follows.
8.3.1 Ion' Exchange/Carbon Adsorption.
The processes of ion exchange and carbon adsorption were adopted 'for
removal of nitrates and pesticides, respectively. At a treatment
facility, the process unit reactors would be arranged in series and
consist of an ion exchanger followed by a granular aotivated carbon
(GAC) filter. Both units would operate as pressure vessels. The ion
exchanger would contain a strong base anion exchange resin that would
serve to displace the negative nitrate ion-(NO~) with a negative
_ chloride ion ICl-}. The resin would be perio~Ycally regenerated with
-sodium chloride {NaC1} when the unit's exchange capacity has bee6 ex-
hausted. Recent testing by the U.S. EnvironmenTal Protection Agency
(EPA)-showed that nitrate-remov-al is effective at an appiication rate-
of 20 gallons per minute per square foot of bed area.- At raw water
nitrate levels that averaged-23 milligrams per liter (mg/1), removals
to less than 10 mg/1 were .consistently realized.' Abcut 20 pounOs of
)laC1 per cubic foot of resin was required for regeneration of the bed
and to remove the nitrate.from she spent resin.
8-19
A GAC pressure filter would follow the ion exchanger for removal of
pesticides by adsorption. This process nas proven to be effective in
removing the pesticide Aldicarb as shown ~y the successful operation
of the existing filter at Greenport's well no. 6-1. It has been
reported that about 107.447 million gallons of water were treated by
the 20,000 pounds of GAC contained in the filter before replacement
was required. Aldicarb levels were reduced from slightly over 7
micrograms per liter (ug/1) to below detectable limits.
8.3.2 Reverse Osmosis
Reverse osmosis was adopted as the treatment process for removal of
nitrates, pesticides and TDS because, as a membrane process in which
the water passes through a barrier membrane, it has proven effective
in rejecting ionic and a m~ority of non-ionic species such as pesti-
cides, bacteria and viruses. For comparison, the processes of elect-
rodialysis removes only ionic species, and thus was not considered.
The reverse osmosis process was selected for treating water produced
from existing wells in Greenport under alternative III(A} which nave,
or have the potential, to contain nitrates, pesticides and high TDS.
It is also the process utilized in the individual home well treatment
systems evaluated under Level I.
Reverse osmosis (R-O) is a membran~ process in which the semipermer
able characteristics of a membrane are utilized to separate contamin-
ants from the feed water under high pressure. To overcome the
natural osmotic pressure of a solution and provide sufficient driving
force to obtain economical water production rates, R-O systems are
typically operated at a pressures of 400 to 500 psi for treating
brackish water.
R-O membrane materials fall into two broad categories: cellulosic and
polyamide. There are also two primary memb6ane configurations:
spiral wound and hollow fiber. For all systems, the feed water is
pressurized using high-pressure pumps_ and conveyed to the membrane
units, where the contaminants are rejected at the membrane wall and
.directed out of the unit as a brine reject stream requiring disposal.
The contaminant-free stream, after passing through the membrane, must
be decarbonated to remove carbon dioxide that has been entrained by
the pretreatment requirement of pU reduction-by addition of acid.
Other pPetreatment requirements include sequestering for scale inni-
bition and cartridge filtration for particulate removal to protect
the membranes. At the completion of the d~carDona:ion process, the
_ treated waten is chlorinated and then p~mped into the distribution
-system.
8-20
m
8.4 ALTERNATIVES FOR DEMAND CENTERS
8.4.1 General DevelopmeE~ Criteria
In accordance with the Level I through V water supply alternatives
presented in Section 8.2, several alternatives were developed and
costs estimated for each demand center. The criteria associated with
the development of Level I alternatives, which consist of individual
home water supply systems, were presented in detail in Section 8.2.1
and will not be repeated in this section. The Level II through V
alternatives generally consist of the development of new public water
supply systems or augmentation of existing systems, with similar com-
ponents for each alternative. These components are summarized on
Table 8-6. The conceptual design criteria for each component that
was adopted for this study in order to enable the development of re-
presentative estimated costs is presented in the following sections.
8.4.1,1 Supply. The supply components include new production wells
ano wel) pumping stations. For the Wading River/Northville and
Riverhead/Jamesport demand centers, the wells would be 350 feet to
ASO feet deep into the Magothy aquifer and sized in accordance with
the estimated year 2000 maximum day demands. For the other demand
centers, new production wells would tap the upper glacial aquifer.
Gravel-packed wells were assumed and 20 feet of stainless steel well
screen was included for cost estimating purposes. The new wells were
sized and spaced in accordance with the criteria presented in Section
7.4.
Two types of well pumping facility arrangements were considered,
depending upon the size and spacing of the wells. For relatively
small-capacity wells spaced in accordance with their zones of in-
fluence, it was assumed that each well would be equipped with a sub-
mersible versical turbine well pump with the motor installed in a
below-ground concrete vault. The well pumps would discharge to a
common header in which water would be conveyed, to a booster pumping
station, where system pressure would be increased to desirable levels
for distribution to customers. For 'relatively large-capacity wells
that are spaced further apart, double pumping in this manner would
not be cost-effective; thus, separate well pumping stations were
assumed, each delivering water into the system. The selection of the
type of system most applicable to an alternative was on a case-by-
case basis and will become apparent during the discussions of the
specific alternatives. The booster pumping stations and the indivi-
dual well pumping stations would include a structure, standby power,
pump and motor and associated piping and valves, HVAC, metering,
electric power and control's. Facilities for the addition of caustic
soda for pH control and sodium hypochtorite for disinfection were
also included, and would generally consist of storage tank, chemical
feed pumps and controls. A hydrooneumatic tank to control pump' oper-
ation and maintain proper system pressures was also included for
those systems where distribution system storage is not warranted.
8-21
TABLE 8-6
COMPONENTS OF ALTERNATIVES
LEVELS II THROUGH V
SUPPLY
o
o
PRODUCTION WELLS
WELL PUMPING STATIONS
TRANSMISSION/DISTRIBUTION
o TItANSMISSION PIPING
0 BOOSTER PUMPING STATIONS (If Required)
o DISlltIBUTION SYSTEM PIPING
0 DISTRIBUTION SYSTEM STORAGE
TREATMENT (If Required)
o CARBON/ION EXCHANGE (PESTICIDES, NITRATES)
o REVERSE OSMOSIS (PESTICIDES, NITRATES, BRACKISH WATER)
ANNUAL OPERATION & h~INTENANCE
o POWER
o LABOR
o CHEMICALS
o EQUIPMENT REPAIR & REPLAC~4ENT
(122/12)
]
t
1
Wells were sized, located and spaced based on providing the estimated
year 2000 maximum day demands. Pumping stations for systems with
distribution system storage would also have maximum day pumping capa-
city, with demands in excess of maximum day supplied from storage.
For hydropneumatic tank systems, estimated year 2000 peak hour pump-
ing capacity was provided, since there would be no distribution sys-
tem storage.
8.4.1.2 Transmission/Distribution. It was assumed that all new
piping would ~onsls[ Ot cemeh't-'~ned ductile iron pipe. Transmission
piping was sized to provide carrying capacity for the estimated year
2000 maximum day demands. A large-scale transmission system was re-
quired only for Level V alternatives, and included piping and booster
pumping sized for year 2000 maximum day demands (except under the
scenario where only average day demands would be supplied to Green-
port). Booster pumping would be required along a transmission system
to maintain system pressures and to supply new distribution system
storage facilities. The booster pumping stations would include a
structure, standby power, a pump, motor, associated pi ping and con-
trols, HVAC and electrical power.
Distribution system piping for subdemand centers was assumed to be
all 8-inch diameter, which should have adequate carrying capacity for
year 2000 demands and fi re requirements. For the isolated neighbor-
hood systems, 6-inch diameter piping was utilized since demands are
relatively small. The length of required distribution system piping
was estimated for each subdemand center based on providing service co
the estimated year 2000 population. As will be discussed later in
this section, piping represents the most costly component in all the
alternatives because of the relatively low housing densities that are
characteristic of the North Fork.
Distribution system storage was provided for .the larger subdemand
centers, especially where the supply source is not centrally located.
Storage provides a volume of water for fife protection Qnd for hourly
fluctuations and also serves to equalize system pressures. The re-.
quired fire protection volume for residential areas was based on a
fire-flow requirement of 750 gpm for a 1-hour duration in accordance
with Insurance Service Office {ISO) requirements for a typical
single-family residential area. Required volume for hourly fluctu-
ations was assumed at 25 percent or-the estimated year'2OOO'maximum
day demand, which is typical of predominantly residential areas. The
sum of these two required volumes represents_ the total required
active storage for a water system. Preliminary siting of storage
facilities was ~ased on area topography, location of supplies and
location of the highest-demand areas. Generally, the facility would
be located so that the highest water demand area would be between the
supply source and the storage tahk, for reliability an~ to equalize
pressures. A site havin~ a high ground elevation is favoraole since
it reduces the required height'of the tank and associated costs. The
8-23
overflow elevation of the tank is based on providing a minimum system
pressure of 35 psi at the highest ground elevation to be served by
the system. Either a standpipe or elevateo steel tank was selected
based on area topography.
8.4.1.3 Treatment. Treatment requirements and associated facilities
were olscusseO ~n section 8.3. In general, an activated carbon/ion
exchange system was adopted, for cost estimating purposes, for treat-
ment of groundwater in the Level II and III alternatives, except for
Greenport's alternative III(A). For that alternative, a reverse
osmosis treatment facility was selected since groundwater produced
from existing Greenport wells is occasionally brackish, in addition
to containing nitrates and pesticides. Individual home well treat-
ment systems, evaluated under Level I, also utilize a reverse osmosis
treatment process.
8.4.1.4 Annual Operation and Maintenance. Annual operation and
m~'lnt~nan~e '~M) requirements for new water systems would include
power, labor, chemicals and equipment repair and replacement. Power
primarily includes the energy required to operate pumping and water
treatment equipment. Labor requirements for new water systems in-
clude a water department staff and crew. The present size and type
of staff personnel for the existing Riverhead and Greenport systems
was used to estimate labor requirements .for new wa~er systems. Water
treatment facility labor requirement estimates took into considera-
tion the size and complexity of the system and were based on past ex-
perience with facilities similar in nature. In general, it was
assumed that water department personnel could operate and maintain
the relatively small activated carbon/ion exchange systems with
proper training; however, the large reverse osmosis treatment plant
under Greenport's alternative III(A) would require a full-time,
qualified operator and staff, since this is a large facility and a
complex process.
It was assumed .that caustic soda for pH control and sodium hypo-
chlorite for disinfection would be added at all new well 'supplies.
8.4.2 Development of Cost Estimates
For each alternative, capital and annual O&M co'ts were'estimated for
the demand 'centers and/or subdemand centers relative to the alterna-
tive components discussed in the preceding section. In order to
facilitate the comparison-of the cost-effectiveness of each alterna-
tive, and to assess relative affordability, costs were expressed as
the estimated annual 'cost per dwelling unit for each alternative and
for each subdemand center. Table 8-7 presents a txpical exomple of
the methodology associated wSth t:is approach.
8-24.
TABLE 8-7
~XAMPLE OF COST DETERMINATION FOR ALTERNAT!VES
o Wading River Sub-Demand Center
Estimated Year 2000 Water Demands
CONSTRUCTION COSTS
-- Alternative III(A)
-- Average Day 360 gpm
-- Maximum Day 690 gpm
Supply -- 2 Wells, each 350 gpm, 350 Ft. Deep
-- 2 Well Pumping Stations, each 350 GPM
Sub-total
Transmission/Distribution
-- Piping; 5.7 mi. 12" dia.; 32.4 mi. 8" dia.
-- Storage; Active Storage = 300,000 gal.
Sub-total
Total Construction Cost
Total Project Cost (including 30%
for engineering and contingencies)
Amortized Capital Cost (40 yrs., 12%)
S 165,000
400,000
$ 565,000 (65)(1)
S 8,735,000 (89%)(1)
540,000 (5%)(1)
$ 9,275,000
$ 9,840,000
S12,790,000
$ 1,550,000
ANNUAL O&M COSTS
o Power, Chemicals, Labor, Maintenance
Total Annual Capital + O&M
Estimated No. of Dwelling Units
Estimated Annual Cost per Dwelling Unit
75,000
S 1,625,000
$ 1,812
$ 900
(1) Percent of total estimated construction cost.
(122/14)
J
1
;]
As shown, estimated construction costs were increased by 30 percent
to account for engineering fees during qesign and construction and
other contingencies such as administrative and legal fees. The total
project cost was then amortized over ¢0 years at 12 percent interest,
which is representative of an annual debt service for repayment of a
long-term revenue bond. Added to this are estimated annual ~M
costs, resulting in a total estimated annual cost for the subdemand
center. Ris cost was then divided by the estimated number of year
2000 dwelling units, resulting in an estimated annual cost per dwell-
ing unit.
Table 8-7 also shows the relative percentage of the major capital
cost components, with piping accounting for 89 percent of the total
cost. l"nis trend is similar for all presently unserved subdemand
centers because of the relatively low housing density in most areas
of the North Fork. Figure 8-4 illustrates this trend and shows that,
on the average, about 87 percent of the costs for alternatives in-
volving new public water supply to serve presently unserved areas is
piping. Figure 8-5 further illustrates the impact of housing density
on piping costs. For example, a typical home owner in Reeves Park,
which contains homes on 3/4- to 1/2-acre lots (on the average) would
pay about S400 a year, representing his share of distribution system
piping cost. This estimate is based on 8-inch ductile iron piping in-
stalled in an existing paved roadway, ihcluding service connections.
For comparison, a typical home owner in Jamesport would pay over
S1,100 a year due to the much lower housing density {3.5-acre lots on
the average). In Jamesport, there is an average of only 25 homes per
mile of roadway, which must support the costs for installing the re-
quired mile of pipe, as compared to 90 homes per mile, on the aver-
age, in Reeves Park. The subdemand center with the lowest density is
Great Hog Neck, where there is an average of only 18 homes per mile
of roadway, resulting in an estimated annual piping cost of over
SI,400 per home.
8.4.3 Wading River/Northville
The total estimated costs of water supply alternatives for the Wading
River/Northville demand center are shown on Table 8-8. They are pre-
sented as estimated annual costs per dwelling unit to allow compari-
sons among alternatives.
8.4.3.1 Level I Alternatives. Level I represents individual Nome
water supply systems'for homes located in presently unserved areas.
The Level I costs shown on Table 8-8 represent a weighted average of
the cost of systems for new homes and the cost of augmenting existing
home systems. The home systems for the expected number of new homes
by the year 2000 would include a well and treatment system. Auoment-
ation of existing home ~ystems would include only the installation of
a trea~nent unit since existing homes presently have wells.
8-25
FIGURE 8-4
1
AVERAGE CONSTRUCTION
COST BREAKDOWN.
FIGURE 8-5
I I ,J I
£$i'IMATED ,I~NUAL COST P£R DNI~LLING UNIT ($)
PIPING C~ST PER DWELLING
AT VARIOUS HOUSING D:J~,~.S
8.4.3.2 Level II Alternatives. Level 1I costs for the Wading
River/~or~vill~ demand center r~present augmentation of the existing
small public water systems located in each of the three subdemand
centers. Augmentation would include: (1) additional well supply, if
necessary, to provide the expected year 2000 water requirements
and/or to provide at least two well supplies (for reliability), and
(2) an activated carbon/ion exchange water treatment system for re-
duction of existing or potential future high levels of nitrates and
pesticides. The existing distribution systems would remain in ser-
vice. Table 8-9 summarizes information on the existing water sys-
tems and augmentation requirements adopted for this study. It snould
be noted that the costs shown on Table 8-8 are average costs per
existing system dwelling unit, and are based on total capital and
annual costs for all existing systems wi thin a subdemand center.
Also, these estimated costs do not include the present annual cost
each homeowner is paying,
8.4.3.3 Level III Alternatives.
under Level iii:
Two alternatives were considered
III(A) - New public water systems to serve the presently un-
served areas only
Existing small public systems augmented for continued
operation, as described under Level II
III(B)
New public water systems to serve the presently un-
served areas and to suDply the existing public systems
- Existing public system supplies discontinued; distri-
bution systems to remain in service.
Figure 8-6 presents the Level III alternatives for the three sub-
demand centers and shows the locations of new well supplies, trans-
mission mains and system storage. The alternative components would
be the same for both III(A) and III(B); however, the supply capacity
would be greater for III(B) in order to provide service to the exist-
ing systems.
AS shown, the new system for Wading River would include two well
supplies, a transmission network and a storage facility. The total
supply capacity would be 700 gpm for III(A) (two wells, each rated at
350 gpm) and 900 gpm for III(B) (two wells, each rated at 450 gpm)
based on expected yeae 2000 maximum day water demands. A pumping
station would be provided at each well. The avemage we)l depth would
be about 350 feet into the ~agothy aquifer, thus treatment was as-
sumed not to De required. A transmission main network of 12-inch
diameter pipe would convey maximum day flows to the storage facility
and to the higher consumption areas. A storage facility was provided
for this subdemand center since it is a relatively large area with
8-30
TABLE 5-9
£XISTI~G PUBL!C WATER SYSTEMS
in the
WADI!(~ ~IVER/NORTHVILLE DE~A)4D CENTER
:Estimated Estimated(i) Existing Supplies Level II
' '2 Augmentation Reouirements
NO. of Yr. 2000 NO. ~Totalk )
System Dwellings Peak Hr. of Well~lCapacity Supply{3) ) Treatment
Wadin~ ~iver
Wading River Water Works B3 85 I i 60 2nd supply ~ 50
Wildwood Shores Assoc. 18 10 1 , 30 2nd supply ) 6
Herod Point Assoc. 22 20 1
Oakwood-on-the-Soun~ g9 105 4 ){unknown) (Assunm OK) ~ 65
Hulse Farms 74 85 2 ' 45 3rd supply ' 50
Ramblewood Motor Homes 128 50 2 I 200 Adequate , 30
Subtotal 394
Baitin9 Hollow/Woodcliff Pk '
Woodcliff Park 200 225 2 ) 220 Adequate , 135
Baiting Hollow Condo's 3~8 50 1 ) 25 2nd Supply i 30
Subtotal 238 ) '
,
Reeves Park [ ,
Reeves Beach Water Co. 184 170 2 ) 165 Adequate 110
Roanoke Water Co. 5~4 4B 2 , 40 Adequate , 30
Subtotal 238
TOTAL 870 ) ,
2_ ,
J
J
l
(1)Gallons per minute (gpm)
(2)Total reported we)l pumping capacity, in gpm
(3)Includes new well at dept~ similar to existing walls, and a well bumping station. Well pumping
capacity acequacy based on peak ~our since there is no distribution system storaQe.
(4)All systems ~uld require treatment consisting of a carbon/ion exchange system. Treatment
oabacity shown is b~sed on max day water demands {in gpm).
1
'.-1
1
I
INSERT FIGURE 8-6
8-32
expected maximum day demands in excess of 1 mgd. Also, since the
supplies are not centrally located, a tank would serve to equalize
system pressures and increase system reliability. Fire protection
would also be provided. A standpipe was selected and located off of
Wading River Road, as shown on Figure 8-6. This site has a rela-
tively high ground elevation {El. 235 +, USGS base) which results in
a required tank height of about 80 feet based on a 315-foot overflow
elevation to provide a minimum of 35 psi at all points within the
system. The required active storage volume would be 300,DO0 gallons
for III{A) and 370,000 gallons for III(B). Distribution system
piping requirements include about 32 miles of 8-inch diameter piping
in addition to about 6 mil es of 12-inch diameter transmission main.
The systems for Baiting Hollow/Woodcliff Park and Reeves Park include
several small-capacity wells, each equipped with a submersible pump
in a vault and connected to a manifold-type piping system. The mani-
fold system would convey flow to a booster pumping station, which
would deliver water to the distribution piping network. The booster
pumping stations would operate off a hydropneumatic tank in lieu of
providing distribution system storage since these subdemand centers
are small and have relatively low water demands.
The supply capacity for Baiting Hollow/Woodcliff Park was estimated
at 190 gpm for III(A) (4 wells at 50 gpm each) and 335 gpm for III(B)
(4 wells at 55 gpm each; 2 wells at 75 gpm each), the higher capacity
being required for III(B) to serve the estimated 238 dwelling units
in the existing systems. The well depth would be about 270 to 300
feet into the Magothy aquifer; thus, it was assumed that treatment
would not be required. About 9 miles of distribution system piping
would be required to serve the presently unserved areas.
The supply capacity for Reeves Park was estimated at 160 gpm for
III(A) (3 wells at 55 gpm each) and 300 gpm for III(B) (5 wells at 60
gpm each). The well depth would be about 275 feet into the Magothy
aquifer. About 5 miles of distribution system piping would be re-
quired to serve the presently unserved areas.
The Level III estimated annual cost per dwelling unit for the three
subdemand centers are shown on .Table 8-8. The Level III(B) costs are
lower since the supply costs were proportioned between the unserved
areas and the existing systems on the basis of maximum day water re-
quirements; thus, they would share the costs. Table 8-10 presents
capital cost estimates for the Wading River/Northville Level III
alternatives.
A Level IV alternative was considered for the Wading R~ver/Northville
demand center which would involve a central groundwater supply source
and a transmission system to provide supply to the three subdemand
centers. It was found that the cost of supply and transmission under
this concept was about-25 percent greater than the total of the sup-
8-33
ply costs for each subdemand center under Level III. This was due to
the length of required transmission pi ping which was substantial
since the centers are relatively far apart. Accordingly, this con-
cept was eliminated from further consideration.
8.4.4 Riverhead/Jamesport
The estimated total annual costs per dwelling unit of water supply
alternatives for the Riverhead/Jamesport demand center are shown on
Table 8-11. The Riverhead Municipal System (i.e., Riverhead, Aque-
bogue subdemand center) was not considered for analysis since an
adequate, high-quality supply presently exists.
8.4.4.1 Level I Alternatives. Level I represents individual home
w~ter supply systems consisting of a well and treatment unit for new
homes, and only a treatment unit for existing homes, The Level I
costs are a weighted average of the costs for existing homes and the
costs for new homes.
8.4.4.2 Level III Alternatives. Level III consists of new public
water systems for Calverton and Jamesport, as shown on Figures 8-7
and 8-8. The Calverton system would include two 40-gpm-capacity
wells and pumping facilities operating off a hydropneumatic tank, and
about 3.5 miles of dlstribution piping. The Jamesport system would
include two 1SO-gpm capacity wells and pumping stations, a distribu-
tion system storage tank with 150,O00'gallons of active storage, and
about 30 miles of transmission and distribution system'piping. A
storage tank was provided for this subdemand center because of its
size, and to assure equalized pressures throughout the system since
the supplies are not centrally located. It would also provide fire
protection throughout the area.
As shown on Table 8-11, the estimated annual cost of the Level I'II
alternative.for Jamesport is S1,530 per dwelling unit. -This high
cost is primarily.due to low housing dehsity and the resulting length
of distribution piping required to provide service throughout the
area. For this area, about 90 percent of the total water system con-
struction costs would be piping. Accordingly, an attempt was made to
reduce public water supply system costs in Jamesport by lim~:ing the
service area to the relatively highJdensity developments located
close to the supply source, as shown on Figure 8-8. This reduction
in service area would reduce the estimated number of dwelling units
from 764 to 440 and the Oistribution system piping from about 30
miles to about SI miles. The expected year 2000 maximum day demand
would also reduce from.30D gpm to about 155 gpm, Which would require
two.80-gpm-capacity wells wi. th s~bmersible pumps,-and one 6ooster
pumping'station with a pe~k hour pumbing.capacity of 230 gpm operatr
lng off a hydropneumatic-tank (a storage tank would not be warranted
with ~he reduction in service area}. From the results o£ this anal?
~-35
I~ISERT FIGURE 8-7
$-37
~NSERT F~GUR£ 8-8
8-38
sis, it was found that the ~nnual cost per awelling unit would be re-
duced by about 33 percent to $1,020. The capital costs were suPstan-
tially reduced by over 60 percent; however, a comparable reduction in
cost per dwelling unit was negated by t~e reduction in the total
number of dwelling units to be served.
8.4.4.3 Level IV Alternatives. Level IV was considered for Calver-
ton only for comparison with Level III costs. Ninety percent of the
Level III costs for Jamesport is for piping; a significant cost
savings would not be realized in a Level IV option by utilizing
Riverhead as a supply source (in lieu of new wells and pumping sta-
tions) since piping requirements would essentially be the same.
Accordingly, Level IV for Jamesport was not considered for further
analysis.
As indicated on Figure 8-7, Level IV for Calverton would simply con-
sist of a metered connection to the existing Riverhead system and
construction of about 3.5 miles of distribution system piping. A
connection could be made to the existing 12-inch main located along
Route 25 near its intersection with River Road. A meter installed in
a vault would also be required to monitor water use for billing pur-
poses. The Level IV cost shown on Table 8-11 includes an estimated
annual water cost that Riverhead would assess Calverton based on
their present bulk rate of S0.60 per 1,000 gallons. This option has
the a~vantage of providing Calverton with a reliable, high-quality
supply and fire protection available from Riverhead's storage
facilities.
Table 8-12 includes capital cost estimates for Level III and IV
alternatives for the Riverhead/Jamesport demand center.
8.4.5 Mattituck/Cutchogue .
The estimated total annual costs per dwelling unit of water supply
alternatives for the Mattituck/Cutchogue demand center are shown in
Table 8-13. The concepts associated with each level of alternatives
were discussed in Section 8.2, and can be summarized for this demand
center as follows:
Level I:
Individual home water supply systems
Level II':
Level III(A): --
Augmentation of the existing neighborhood sys-
tem (Captain Kidd'development) in Mattituck
West
New systems for presentily unserved areas -
Captain Kidd system augmenteU as per Level .ii
8-39
]
]
]
]
]
1
Level III(B):
Level V: -
Level V(A): -
Level V(B-1): -
Level V(B-2):
Level V(C-1,2): -
Level V(D-1):
Level V(D-2): -
New systems for presently unserved areas and
to supply Captain Kidd system
Captain Kidd system supply to be discontinued
(except for emergency use); distribution sys-
tem to remain in service
Supply from potable groundwater sources in
Riverhead
Transmission system from supply to demand
centers
Distribution system piping and storage for
demand centers
Mattituck/Cutchogue demand center (year 2000
maximum day)
Mattituck/Cutchogue and Southold/Greenport
demand centers {year 2000 maximum day)
Mattituck/Cutchogue demand center (year 2000
maximum day)
Southold/Greenport demand center (year 2000
average day)
Continued use of existing supplies, as re-
quired
(Regional alternatives for the Greenport
Municipal System presented in Section 8.4.6)
Mattituck West and East Subdemand centers
(year 2000 maximum day)
Greenport Muni.cipal System (year 2000 maximum
day demanU)
Mattituck West and East subdemand centers
(year 2000 maximum day)
Greenport Municipal System (year 2000 average
day)
Conlinued use of existing supplies, as re-
quired.
8-41
B.~.5.1 Level I Alternatives. The costs shown on Table 8-13 are a
weTg'hted average of existing home and new home costs, based on %ne
expected number of new homes by the year 2900. Treatment would no~
be required in the Little Hog Neck and New Suffolk subdemand censers
since high levels of nitrates and/or pesticides are not expected in
these areas.
B.~.5.2 Level II Alternatives. Level II for this demand center
applies only to the Mattituc~ West subdemand center, which contains
an existing neighborhood system serving the Captain Kidd development.
It is estimated that by the year 2000 the population would be about
580, housed in 154 dwelling units, wi th estimated water demands of 32
gpm on an average day basis, 96 gpm on a maximum day and 160 gpm
during a peak hour. Presently, the system has two wells with a com-
bined pumping capacity of 300 gpm; therefore, the supply is consider-
ed adequate. The estimated annual cost per dwelling unit of S300 re-
Jects the cost of a IO0-gpm capacity activated carbon/ion excnange
trea~ent facility.
8.4.5.3 Level III Alternatives. Level III alternatives for this
oemanO center are simi'lJr'~n ~ature to those developed for the Wading
River/Northville demand center. This level involves development of
individual public water systems for each subdemand center including
supply, trea~nent (if necessary) and tr.ansmission and distribution
pi ping. Layouts of the major system facilities for each suboemand
center are shown on Figure 8-9. Table $-14 summarizes information on
the components of the alternatives for each demand center and in-
cludes estimated supply and treatment system capacities and piping
requirements.
For each subdemand center, a system consisting of multiple wells
(with submersible pumps) discharging to a header system for convey-
ance to a booster pumping station was selected. Multiple wells would
provide increased reliability and assure that the aquifer is not
overstressed at one location, since groundwater withdrawals would be
Qistributed over a wide area. This should prevent upconing and,
accordingly, saltwater intrusion. For the subdemand centers requir-
ing treatment, the booster pumping station would be contained within
the treatment facility structure and would be operated off a hydro-
pneumatic tank, except in Mattituck South, where a distribution sys-
tem storage tank is suggested. As is evident on Figure 8-9, the pro-
posed well location for Mattituck South is actually outsiQe the
demand center boundary at the western extremity. Accordingly, in
order to equalize system pressures and to reOuce water transmission
requirements, a storage tank, centrally located at a high ground ele-
vation as shown, was provided. The required active storage volume
for fire protection and hourly fluctuations is estimated at Z25,O0~
gallons. The remaining subdemand centers would not warrant system
storage, either because of their relatively small size and resulting
I:ISERT FIGURE 8-9
low water demands, or a centrally locateo supply. For these areas,
peak hour pumping capacity would be requir~, with the pumps operated
off the nydropneumatic tank (which serves to control pump cycle time
and system pressures).
As with the Wading River/Northville demand center, the costs of Level
III(B) for MattitucK West include supplying the Captain Kidd system
from a new, central source that would also supply the unserved areas.
Accordingly, the supply and treatment costs were proportioned between
Captain Kidd and the unserved areas based on maximum day water re-
quirements. As shown on Table 8-13, Level III(BI would be more ex-
pensive for Captain Kidd since it includes a portion of the total
supply and treatment costs, whereas Level ~II(A) includes the addi-
tion of only a treatment system to their present supplies.
For this demand center, piping represents an average of 53 percent of
the Level III costs shown on Table 8-13. Indian Neck has the lowest
housing density within the demand center (average of 30 homes per
mile of roadway) and the highest Level III costs due to piping re-
quirements. Mattituck West and East have the highest density within
the demand center (average of 60 homes per mile of roadway) which re-
flects the lower Level III costs. However, in all subdemand centers,
Level I proved to be less expensive than Level III.
8.4.5.¢ Level IV Alternatives. Level IV for MattitucK/Cutchogue was
not evaluated in detail since a significant cost savings would not be
realized compared with Level III. Level IV would include a central
supply serving the entire demand centerl however, piping requirements
and associated costs would be essentially the same as the sum of the
piping costs for the subdemand centers under Level III. Since an
average of B3 percent of the Level III costs is piping, and consider-
ing that a central supply would require additional transmission
piping and, most likely, distribution system storage, it is estimated
that only a 5 to i0 percent cost savings would be realized unoer a
Level IV option. Refering to Table 8-13, Level IV costs would s~ill
be significantly nigher than Level I costs, except in Mattituck West
and East where the difference would not be as significant. For these
subdemand centers, additional an.alysis is warranted and was performed
under Level V. This will be discussed in the following sections.
8.4.5.5 Level V Alternatives. Level V for Mattituck/Cutchogue in-
cludes construction of groundwater supply and production facilities
in Riverhead, a water transmission system from the supply sources to
demand centers, and distribution system piping and storage within the
demand centers. As discussed earlier, Levels V(B) and V(D) also in-
clude service to Greenport. and essentially involve a continuation of
the water transmission system to that area. For these options, the
supply and transmission costs would be shared by the demand centers,
proportioned on the Oasis of design flows. As shown in Table
the cost of scenarios 1 and 2 under bot~ Levels V(B) and '~(O/ are
$-46
essentially equal for Mattituck/Cutchogue since the scenarios apply
only ~o Greenport. Scenario 1 would provide maximum day supply to
Greenport, while scenario 2 would only provide up to average day
supply, wi th Greenport's existing supplies re~aining in service.
Under all Level V alternatives, maximum day supply would be provided
to Mattituck/Cutchogue since there are no existing supplies within
this area, Level V for Greenport will be discussed in Section 8.4.6.
Level V(D) was developed and evaluated primarily to determine if the
Level III costs for ~attituck West and East could be reduced by uti-
lization of a regional supply source. Since a regional supply would,
most likely, not be developed only for these subdemand centers, the
Greenport Municipal System was also incorporated into this Level for
comparison with the costs for Greenport's Level V(C) (discussed in
the next section).
A layout of the components of Level V, specifically Level V(B), is
shown on Figure 8-10. Table 8-15 summarizes pertinent information on
each component. Supply would consist of deep production wells in
Riverhead, preliminarily located as shown on Figure 8-10. Each well
would tap the Magothy aquifer and would average 350- to 450-feet
deep. Treatment for nitrates and pesticides removal was assumed not
to be required since, reportedly, the.Magothy aquifer in this loca-
tion Goes not contain these constituents. Each well would include a
pumping station equipped with a vertical turbine well pump, standby
power, chemical addition facilities (for disinfection and pH adjust-
ment) and other associated piping and control appurtenances. Total
supply (and transmission system) capacity was based on the to~al
estimated year 200D maximum day demands for the areas to be served
for Levels V(A), V(B-1), and V(D-1). For Levels V(B-2) and V(D-2),
supply and transmission system capacity was based on year 2000 maxi-
mum day demands for Mattituck/Cutchogue plus year 2000 average Oay
demands for Greenport.
Transmission system pi ping would consist of cement-lined ductile iron
pipe with a maximum pipe size for each-alternative as indicated in.
Table 8-15. This pipe size would be required for the section between
the most easterly production well and the connection to the first
storage tank in the Mattituck/Cutchogue area, and would convey up to
the total design flow for the entire service area. Beyond. the first.
tank, th~ pipe size would reduce in size as it heads toward Green-
port, in accordance with the reduction in required carrying capacity_
as demands are satisfied. Under Level V(D)~ the transmission system
would follow the same route as indicated in Figure 8-10; however, the
-pipe sizes wo~d be less and only ohe new s:orage facility to serve'
Mattituck West and East Would be required. Booster pumping stations
would be provided along the pipeline in order to'maintain-system
pressures, which would gradua)ly decline due to pipe friction as t~e.
water ~ows east. The s~ations woulO include a centrifugal pump,
standby power and other related appurtenances, housed in a super-
8-47
J
INSERT FIGURE 8-10
8-48
J
structure. For this Conceptual analysis, minimum transmission system
pressures were assumed to be 35 psi and maximum pressures 100 psi.
As presently conceived, the system would aave the capability of fill-
ing proposed storage facilities in the Mattituck/Cutchogue area. For
Levels V(B) and V(O) the pressures at the eastern end of the system
would be sufficient to supply the Greenpor% system while maintaining
their present system pressures. System pressures within the Matti-
tuck/Cutchogue demand center would be controlled by the water level
in the storage tanks, which would provide a minimum of 35 psi at
highest ground elevations. Water would be delivered to consumers
through a distribution piping system containing about I30 miles of
piping, required to serve the entire demand center.
As shown on Figure 8-10, the transmission main route selected for
this analysis generally follows Route 25, which traverses the areas
%o be served. Transmission piping costs include allowances for uti-
lity crossings, pavement restoration and policing. Two alternative
routes were also considered, as follows:
Option 1 - Generally follows North Road.
Option 2 - Along the existing right-of-way (ROW1 of the Long
Island Ligh%ing Company (LILCO). This option assumes
access could be obtained from the utility.
These route options are also shown on Figure 8-10. An analysis of
the estimated transmission system piping requirements and related
costs associated with each option was performed only for Levels V(C)
and V(D) since only these alternatives have the potential to be as
cost-effective as Level I, as is evident in Table 8-13. The results
of the analysis for Level V(C) (Greenport Municipal System) will be
presented in the next section. For Level V(D), it was found that the
amount of piping would be less for options 1 and 2, and the pipe in-
stallation costs for option 2 would be about 10 percent less expen-
sive since paving, utility crossing and policing would not be re-
quired along the LILCO right-of-way. The impact on Level V(D) costs
for the route options is summarized as follows (for Mattituck West
and East only):
Route 25 Option i Option 2
V(D-!) V(D-2) ¥(O-i) V(O-2) V(O-k) V(O-2)
Length of Piping
~equired, miles*
19.5 15.2 18.8 14.2 15.7 12.5
Annual Cost per
Dwelling Unit S685 S660 S665
'i'ncludes service to Greenport also and includes ~ran~mission piping only.
~-50
A significant cost savings would not be realized since, as discussed
earlier, over 83 percent of the total capital cost of Level V(D) for
Mattituck West and East is distribution system piping, which tends to
reduce the overall impact of cost savings associated with the trans-
mission system route options. However, Level V(D) costs are lower
than Level III costs, regarUless of transmission system routing, for
two reasons: (1) treatment would not be required, and (2) Greenport
would pay for a portion of the supply and transmission system. Level
I, however, still appears to be the lowest-cost option available to
all subdemand centers within Mattituck/Cutchogue.
Table 8-16 presents the capital cost estimates for Level Iii and V
alternatives for the Mattituck/Cutchogue demand center.
8.4.6 Southold/Greenport
The estimated total annual costs per dwelling unit of water supply
alternatives for the Southold/Greenport demand center are shown on
Table 8-17. The concepts associated with each level of alternatives
were summarized in the preceding section and so will not be repeated
here.
8.4.6.1 Level I Alternatives. Level I applies to Great Hog Neck and
~ast Mar~on on)y ano includes individual home water supply systems.
In both subdemand centers, treatment would probably be required;
therefore, it was included in the Level I costs.
8.4.6.2 Level III Alternatives. Level III consists of new public
water systems for Great Hog Neck and East Marion, and augmentation of
the existing Greenport Municipal System. Similar to the other demand
centers, Level III for Great Hog Neck and East Marion includes a
multiple well-type supply system feeding a booster pumping station
and water treatment facility, as shown on Figures 8-11 and 8-12. For
Great Hog Neck, a distribution system storage tank was provided due
to the size of the area and the availability of a relatively high
ground elevation (El. 70 feet, USGS base) near the supply source.
Table 8-18 summarizes information on t~e components of Level III
alternatives for the two subdemand centers.
As is evident in Table 8-17, the Level III costs for Great Hog Neck
and East Marion are relatively high, primarily because of the length
of required piping and associated costs. Great Hog Neck has she
lowest density of any subdemand center on the North Fork, with an
average of only 18 ho~es per mile of roadway. To provide water ser-
vice throughout the area, over 28 miles of piping would-be required
to serve only about 500 homes. Similarly, East Marion also has a
very low density with an average of aDout 40 homes per mile of road-
way. It is apparent that these areas are not conducive to a public
water system because of the lack of an aeequate population base.
8-51
INSERT FIGURE 8-11
8-5,$
INSERT FIGURE 8-12
8-55
Two Level III alternatives were evaluated for the Greenport Municipal
System, as follows:
III(A)
Reverse osmosis water treatment plant
Additional distribution piping and storage
Great Pond Water Supply System
Reverse Osmosis water treatment plant
Additional distribution piping and storage.
The components associated with these alternatives are shown concep-
tually on Figure 8-13. As indicated, additional distribution system
piping (8 miles) and storage would be required under each alterna-
tive.
Year 2000 distribution system storage requirements were estimated
assuming that storage of 25 percent of the estimated year 2000 maxi-
mum day demand would be provided to account for hourly demand fluc-
tuations. In addition, a fire-flow volume was also included based on
a fire ~ow of 1000 gpm for a 1-hour duration. The resulting total
required storage volume is 700,000 gallons. The existing system
storage facility, which is located on Moores Lane, has a capacity of
300,000 gallons of active stDrage, resulting in an estimated deficit
of 400,000 gallons. Accordingly, alternatives III(A) and III(B) in-
clude costs for a 400,O00-gallon elevated sto~age tank with the same
overflow elevation (El. 178 feet, USGS base) as the existing tank.
This would allow continuation of the present system operating condi-
tions and would maintain current system pressures, The tank location
would be somewhat dependent upon the water supply plan ultimately
selected for Greenport and a hydrualic analysis of ~ne piping system,
which is beyond the scope of the present study. A possible tank
location would be adjacent to the existing tank, which would serve to
centralize system storage and equalize system pressures if a new sup-
ply source were located in the western portion of Greenport.
The components associated with ~evel III(A) include a 15OD-gpm capa-
city reverse osmosis water treatment plant (WTP) which would serve to
remove nitrates, pesticides and total dissolved solids from the raw
groundwater. Under this option, the existing carbon filter would be
removed at well 6-1, increasing the capacity from bOO gpm to its
original 550 gpm. With well 6-2, the total Plant 6 capacity would be
700 gpm. Plant 7 would also be utilized as a raw water source and
has a pumping capacity of 350 gpm. The third proposed raw water
source is an existing farm well located off of Middle Road near
Tuckers Lane, known as Dononue's Farm well. It has a reported yield
of about 450 gpm. It was assumed that renovations would include a
new pump and motor and associated piping an~ appurtenances, electri-
cal controls anO a new structure. Cleaning of the ~ell screen may
also De required.
8-56
INSERT FIGURE 8-13
8-57
At plants 6 and 7, the piping connections to the existing !2-1-~n
main in Middle Road would be blocked (or valveo) an~ a new raw
transmission system constructed from the wells, including Donon~e'~
Farm well, to the WTP. It was assumed that the plant would De
located along Middle Road opposite the Donohue's Farm well, as
on Figure 8-13. The raw water would be metered and then chemically
treated with sulfuric acid and sodium hexametaphosphate (SHM?! ~ri~r
to filtration. The acid is required to lower the pH to prevent
cium carbonate deposition and fouling of the m~Dranes. £HMP !s
added to prevent precipitation of iron, manganese and/or o~her ~cn-
stituents which would also foul the membranes. The chemically
treated water would then pass through cartridge fii:ers wnicn
remove any suspended solids greater than 10 microns in size. T~is
protects the membranes and increases the length of time between ~eq-
brahe cleaning and, eventually, replacement. High-pressure pum:s
would boost the pressure to about 300 to 400 psi and the
treated water would enter the R-O membrane units. The brine
which is that portion of the water that does not pass threugn
membranes, would be collected and transported out of the 21an~ f:r
disposal. Typically, the volume of this waste stream averages
20 to 25 percent of the total plant fl.ow, resulting in an average
flow rate of about 300 to 375 gpm. It would contain nitrates,
pesticides, total dissolved solids and other constituents f~un~ i~
the groundwater, in concentrations approximately four co Five ti~es ,
greater than the raw groundwater, tt was assumed for %his ~ucS
the waste stream could be discharged into Jockey Creek since the
dilution offered by the creek would, most probably, negate ~ny
rial adverse effects. However, this would require de~aileQ investi-
gations including receiving water analyses and impact assessment? in
addition to approvals from local, State and federal regulatory agen-
cies.
The 75 to 80 percent of the water that does pass through the mem-
branes would require decarbonation to remove carbon diQxide an¢ 3the
dissolved gases that may be entrained within the flow stream ~ue
the addition of acid and the lowering of the pH. Removal of car~n
dioxide would serve to increase the finished water pH and prevent
buildup within the distribution system. Accordingly, a forceo-craft
degassifier, which operates similarly to an mir-stripping tower coq-
manly used for ammonia removal, was included in the cost estima~a
the plant. Sodium hypochlorite, or another form of chlorine, ~ou~
then be added to the flow stream for disinfection prior to ~u~iq~
the finished water into the distribution system.
~he treatment facilities would be contained within a one-story s:~er-
structure, assumed to-be constructed of concrete-blocK wi~ ·
facade. The approximate building size would be on the order of
to 3,500 square feet. Staff requirements would include one
plant operator and one full-time assistant. It was assumed that
Greenport Water Department personnel would also ~e availaol~ t~ ~s-
sist in WTP maintenance and repair when requ~reo.
8-58
As discussed above, 20 to 25 percent of the raw water entering the
plant would be rejected; thus, the plan~s actual production capacity
would be in the range of 1,100 to 1,200 gpm. Since the estimated
year 2000 maximum day demand for GreenDort is 1,780 gpm, some of the
existing supplies must remain in service. It was assumed that plants
4, B and 8 would remain in service and be used, when required, for
peaking purposes. It was also assumed that with reduced usage of
these wells and blending with the WTP finished water, overall system
water quality would comply with all County and State water quality
standards.
The Level III(B) alternative, for Greenport is based on a concept that
was discussed previously and was developed in more detail for this
study in order to assess potential costs and how they compare with
other Greenport alternatives. It involves the use of Great Pond,
which is located in the northwest portion of Greenport's system, as a
water supply source. It has been reported that the nitrate levels in
Great Pond water are considerably lower than levels in the ground-
water of the surrounding area. It has been further assumed that this
was most likely due to a natural denitrification process occuring in
the bottom sediments of the pond, where bacteria would convert
nitrates into nitrogen gas. It has been estimated that the potential
yield of the pond would be in the order of 500 gpm; however, it could
be as high as 1,000 gpm.. Level III(B) is based on the assumption
that Great Pond water contains acceptable levels of nitrates and that
no treatment, other than disinfection, would be required. A system
capacity of 500 gpm was also assumed.
A concept of utilizing Great Pond water without a high degree of
treatment was developed for this study and is shown schematically on
Figure 8-14. It involves the construction of a groundwater injection
system including a pond water pumping station. Pond water would be
withdrawn from the pond and injected into the upper glacial aquifer
through a number of injection wells arranged around a central produc-
tion well. The production well would be a typical well and pumping
station containing chemical addition facilities and the necessary
system control s. This arrangement serves two purposes: (1) the
injection wells would increase ~he water table elevation around ihe
production well, creating a hydrologic barrier between the well and
the aquifer, which would prevent "short-circuiting" by assuring that
pond water and not contaminated aquifer water was delivered to the
system, and (2) pond water would travel through several feet of soil
before it reaches the production well, taking advantage of the
natural purifying action of the soil to reduce turbidity and increase
overall water quality. It must be emphasized that this is a concept
only, and its applicability is dependent upon actual pond water qual-
ity, grounowater conditions and movement in the area and subsurface
soil conditions. A full engineering investigation would be required
prior to serious consideration of this alternative. The estimated
cost of such an investigation was included in the Level III(B) cost
estimate {aparoximately S90,000), based on performing the following
work tasks:
8-59
F I Gt;P,E 8-14
'" ) PRODUCTION
{ WELL AND PUMP
INJECTION WEL. k
PIPING SYSTEM
OND WATER
PUMP STATION
GREAT
SUCTION PiPE
POND
'R,~NSMISSION (TYPICAL) m
MAIN TO
SYSTEM
PLAN
WATER TABLE WITH
SYSTEM IN OPERATION
GROUND
)UCTION WELL
WELL
TYPIC AL')
NORMAL WATER
TABLE
GREAT POND
SECTION
- Site investigation
- Exploratory program (including test wells)
- Installation of monitoring wells
- Extended duration pump test (4 months)
- '~ater quality sampling and analyses
- Analysis of results and development of recommendations
- Preparation of engineering report.
Since this system would deliver only 500 gpm of finished water, Level
III(B) also includes construction of a 1,050-gpm (1.5 mgd) reverse
osmosis water treatment plant, similar to Level III{A), which would
treat water from plants 6 and 7 only. Assuming a 25 percent reject
by the R-O process, the WTP production capacity would be about BOO
gpm, resulting in a total of 1,300 gpm of potable water production
including the Great Pond system. Utilization of Greenport's other
existing wells, to a limited extent, would be required under this
alternative, similar to III{A), to provide up to maximum day produc-
tion capacity (1,780 gpm).
As shown on Table 8-17, the estimated cost of Level III(B) is
slightly less expensive than III(A) s~nce the Great Pond system does
not include treatment. If the Great Pond system could be developed
as presently conceived, which would be determined from the above-
described engineering study, Level III{B) would be more
cost-effective than III(A).
8.4.6.3 Level IV Alternatives. Level IV low the Southold/Greenport
Oeman~ center.was not considered for reasons similar to those dis-
cussed in connection with the Matticuck/Cutchogue demand center.
Since about 90 percent of the Level III costs for Great Hog Neck and
East Marion are for distribution system piping, a significant cost
savings would not be realized by supplying these areas from'the
Greenport system. Estimated costs per dwelling unit would still be
over S2,000 for Great Hog Neck and close to ST, O00 fo~ East Marion.
8.4.6.4 Level V Alternatives. The components and preliminary desigQ
Criteria assoclateo wlt~ Level V alternatives were described in Sec-
_tion 8.4.5.5, ~i.nce most of the altrnatives aiso include the Matti-
tuck/Cutchogue demand center. In summary, ¥(A) involves Ma~ti:ucK/
Cutc~ogue only and does not include Greenport, .V(B) provides service
to Mattituck/Cutchogue and ~he Southold/Greenpor~demand den~er~,
V{C) provides service on)y to the Greenport Municipal S~stem, and
¥(D) .provides service' td ~he Mattituck Wes~ and East su~emand
centers in addition to the ~reenport Municipal System..For each
8-61
alternative, the water supply from deep wells in eastern Riverhead
would be conveyed to the demand centers by a transmission piping and
booster pumping system. A conceptual layout of the components of
Level ¥ alternatives is shown on Figure 8-10, which also shows the
transmission pipeline route options.
As indicated in Table 8-17, two scenarios were considered for alter-
natives V(B), V(C), and V(D). Alternatives ¥(B-1), V(C-1) and
would brovide supply from Riverhead equal to Greenport's estimated
year 2000 maximum daily demand. Under these options the use of
Greenport's existing well supplies would be discontinued. Alterna-
tives V(B-2), ¥(C-2) and V(D-2) would provide supply equal to Green-
port's year 2000 average daily demand, with selected existing well
supplies remaining in service, in order to provide maximum day pro-
duction capability.
Under all alternatives, transmission system connections would be made
to Greenport's existing system at its western extremity. The hydrau-
lic grade line (HGL) of the transmission system would exceed Green-
port's HGL at that location in the system in order to convey water
into Greenport's system. Distribution system piping and storage
would be required fer Greenport as discussed under Level III in Sec-
tion 8.4.6.2, and also for Great Hog Neck and East Marion under
alternative V(B). Supply costs were distributed to the demand
centers {or subdemand centers) on the basis of design flow which,
except for Green~ort under V(B-2), V(C-2) and ¥(D-2), was the esti-
mated year 2000 maximum day demand. Transmission system costs were
also distributed based on flow; however, they were also dependent on
proximity of the demand center in relation to the transmission sys-
tem. For example, referring to Figure 8-10, which depicts alterna-
tive V(B), estimated costs for the transmission system from the supp-
lies to the eastern storage tank serving Mattituck/Cutchogue were
proportioned between Mattituck/Cutchogue and Soutnold/Greenport based
on year 2000 maximum day demands. HoweveK, costs for the remaining
portion of the system, from the tank to the connection(s) with Green-
port's system, were allocated to Southo~d/Greenport only.
A~ mentioned above, scenario 2 (i.e., ¥(B-2), V(C-2) and V(D-2)) in-
cludes continuation of the use of certain existing supplies in Green-
port, since only year 2000 average day demand would be supplied from
the Riverhead wells. This scenario-was considered in 6rder to deter-
mine the impact-on costs to Greenport by reducing the ~iverhead sup-
ply requirement and associated facilities. For alternatives V(C-2)
and V(D-2), the estimate~ year 2000 average day that would be supp-
lied to the Greenport Municipal System is 660 gpm. Since t~e esti-
mated maximum day demapd is 1,780 gpm, a system supply capability in
Greenport of about 1,120 gp~_ mus: be maintained. -Reporte61y, the
highest quality well supplies in Greenport are Plant 6. which is
equipped with a carbon filter (550 gpm), Plan: 7 (350 gpm) and Plant
8 (350 gpm). The total combined capacity of these supplies is i,,250
5-62
gpm. Reportedly, plants 7 and 8 occasionally experience high chlor-
ide concentrations; however, with reduced usage, the quality of the
Greenport wells remaining in service would improve and the overall
system water quality would comply with all federal, State and County
standards. Prior to serious consideration of this scenario, further
engineering study and water quality analyses on Greenport's wells
would be required.
Referring to Table 8-18, the cost impact of distribution system
piping is apparent for Great Hog Neck and East Marion, since there is
essentially no difference in cost between Level III and Level V(B).
Level III involves a local, treated groundwater supply while under
Level ¥(B) the supply would emanate from Riverhead. Source of supply
has little, if any, significant impact on costs in these subdemand
centers since, under either level, ~iping represents about 90 percent
of total capital costs. As mentioned earlier, these subdemand cen-
ters are not conducive to support of a public water system.
The Level V costs for the Greenport Municipal System are similar for
each alternative. There is a slight cost advantage to Greenport if
the supply and transmission costs were shared with Mattituck/Cutch-
ogue under V(B) or with only Mattituck West and East under V(D).
However, as discussed in Section B.4.5, Level V(B) does not appear to
be cost-effective for Mattituck/Cutchogue if compared with Level I.
Levels V(C) and V(D) do appear to be cost competitive with other
options, especially with Level III for Greenport. If Greenport's
existing supplies were to remain in service under scenario 2, costs
of Levels V(C) and V(D) would be reduced an estimated 20 to 25 per-
cent.
As discussed in Section 8.4.5, alternative transmission main routes
were considered for Levels V(C) and V(D), as shown on Figure 8-10.
The route selected for detailed transmission system analysis gener-
ally follows Route 25 and the costs shown in Table 8-17 reflect that
route. The two options considered were: (1) generally along North
Road (Route 27) and (2) generally along the LILCO right-of-way, as-
suming access would be available. The cost comparisons for the
Greenport Municipal System were su~arized as follows:
Greenport Municipal
System
Estimated Annual Cost Per Dwelling Unit
Route 25 Option i Option 2
V(C-l) $530 S520 S475
¥(C-2) 430 420 465
V(D-1) 515 510 395
¥(D-2) 410 400 380
2-63
As indicated, a significant cost savings would not be realized if
Option 1 were pursued; however, Option £ costs do average about 10
percent less than the Route 25 costs since paving restoration would
not be required along the LILCO right-of-way. Costs for utilizing
the easement, however, were not included in the above estimates.
alternative V(C) or V(D) were considered for eventual implementation,
Option 2 should be further investigated and LILCO contacted to deter-
mine if use of their easement would be allowed.
Table 8-19 presents the capital cost estimates for Level III and V
Alternatives for the Southold/Greenport demand center.
8.4.7 Orient
The estimated total annual costs per dwelling unit for water supply
alternatives in the Orient Demand Center are summarized in Table
8-20.
TABLE 8-20
ESTIMATED ANNUAL DWELLING UNIT
COSTS CF WATER SUPPLY ALTERNATIVES
FOR THE ORIENT D~4AND CENTER
Estimated Ahnual
Estimated Number of Level
Year 2000 Dwelling Units I
Cost per Dwelling Unit
Level
I!I
593 $620 S.1,055
8.4.7.1 Level I Alternatives. As discussed in previous sections,
Level I consists of indivioual home waier supply systems and includes
the installation of a ~reatment unit in existing homes, and the in-
stallation of a well plus a treatment unit for new homes. Treatment
would consist of a reverse osmosis system for removal of nitrates,
pesticides and/or total dissolved solids. The costs shown in Table
8-20 reflect a weighted average of the costs of facilities for exist-
ing homes and the costs of facilities for new homes, Daseo on the
estimated number of new .homes by the year 2000.
~.4.7.2 Level-III Alternatives. As with the other demand centers,
the Level III alternative consists of a new groundwater supply, a
water treatment system and ~ transmission/distribution system.
Figure 8-15 shows a conceptual layout of the m~or system components.
Two wells, approximately 90-fqet deep, woulU be constructeO, as
8-65
shown, and tap the upper glacial aquifer. Each well would be equip-
ped with a submersible vertical turbine pump with the motor located
in an underground vault. The wells would be sized for a total pro-
duction capacity of 200 gpm (100 gpm eachl which is equivalent to the
estimated year 2000 maximum day demand for Orient. Water would be
conveyed to a treatment facility which would employ the processes of
ion exchange and carbon adsorption for removal of nitrates and pesti-
cides. Chemicals for disinfection and pH control would also be
applied. Treated water would then be pumped into the distribution
system for delivery to consumers. The booster pumping station would
operate off a hydropneumatic tank and would include standby power.
It is estimated that about 14 miles of distribution system piping
would be required to serve this area. As with Mattituck/Cutchegue
and several other areas on the North Fork, the relatively low density
of Orient results in significantly high piping costs. The density of
Orient is essentially the same as East Marion (an average of about 40
homes per mile of roadway) resulting in comparable Level III costs
which, in both cases, are almost double the Level I costs.
8.4.7.3 Level IV and V Alternatives. Levels IV and V were not con-
~oereo for Orient s~nce a preliminary analysis revealed t~at costs
would be greater than Level III. This is primarily due to the
transmission piping required to serve this relatively isolated area
from the Greenport system. This piping requirement essentially
negates any potential cost savings resulting from the elimination of
the water treatment system required under Level III.
Table 8-21 presents the capital cost estimate for the Level
alternative in Orient.
III
TABLE 8-21
CAPITAL COST ESTIMATES
ORIENT DEMAND CENTER
(ENR-3800)
LEVEL III
Supply $ 185,000
Transmission and 3,180,000
Distribution
Treatment 400,000
Total Construction Cost S3,765,000
Total Projec~ Cost S4,895,000
8-68
:q
8.4.3 Isolated Neighborhood Systems
The estimated costs for Level I and Level 11 water supply alterna-
tives for the isolated nei§hborhood systems are summarized on Table
8-22. As indicated, treatment would not be required for the neigh-
borhoods located in the western portion of the North Fork because
uncontaminated groundwater sources are available.
As with several of the subdemand centers located throughout the North
Fork, distribution piping represents a substantial portion of the
Level II costs. Although these neighborhoods are not as sparsely
populated as several of the eastern subdemand centers, the housing
density is relatively low, averaging about 60 homes per mile of road-
way.
The required piping and associated costs to provide public water ser-
vice to neighborhood homes is the major reason for the higher Level
II costs, as compared to Level I.
Table 8-23 presents the capital cost estimates for the Level
Alternatives for the neighborhood systems.
8.5 COMPARISON OF ALTERNATIV£S
Several criteria must be considered when comparing and evaluating
water supply alternatives for the North Fork. The criteria used in
the evaluation include the following:
Cost
Reliability
Implementability
Environmental considerations
Adaptability to future changes.
8.5.1 Cost
The cost of the various alternatives is perhaps the most straightfor-
ward criteria to evaloate, and certainly one of the most important.
The cost is comprised of two components:
The capital requi~ed to construct the components of the sys-
tem (i.e., source of supply, transmission/distribution, and
treatment)
8-69
TABLE 8~22
ESTIMATED COSTS OF WATER SUPPLY ALTERNATIVES
for
ISOLATED NEIGHBORHOOD SYSTEMS
ESTIMATED NO. ESTIMATED ANNUAL COST PER DWELLING UNIT
OF YR.2DDO ................ 1 .............
HB~GHBO~HOOD SYSTBMS BWELLING UNITS ~;~ i [~ ii
$ $
I. Lake Panamoka 115 230* 485*
2. ~t. 25 S. of Scuttle Hole 44 230* 865*
3~ lt. 25 N. of Grunl~an Airport 150 230* 615'
~. Salting Hollow 43 325* 1000'
5. Off Tuthill Lane 71 225* 675*
6. Duck Pond Point 70 605 785
7. Rt. 27 near Depot Lane 43 605' 930
6. Goldsmit~ Inlet ~32 605 665
g. Great Pond ]65 605 805
The cost of administering, operating and maintaining the
system: labor, power, chemicals, supplies and routine main-
tenance; this cost is generally referred to as the O&M cost.
In order to compare the total cost of each of the alternatives, it
was necessary to place the capital and O&M costs on a common basis.
The approach utilized in this study was to amortize the total capital
cost (using an appropriate interest rate and payback period) to yield
an annual cost required to finance the construction of the project.
This annual amortized cost was then added to the annual O&M cost to
determine the total annual expenditures required. The annual costs
were then divided by the estimated number of dwellings served by the
alternative (in the year 2000) to develop average annual costs per
dwelling unit. These costs were then used as the basis of comparing
the alternatives.
8.5.2 Reliability
Reliability addresses a series of considerations which bear upon the
ability of the water supply system to consistently operate in a
satisfactory manner. The following aspects were considered:
(1) The reliability of the source of supply to provide,water
which meets required quality standards
{2) The reliability of the treatment processes employed to re-
move objectional constituents found in the raw water
(3) The reliability of equipment and hardware to consistently
remove contaminants from a raw water supply
(4)
The reliability of the water supply system to consistently
deliver water of adequate pressures and volumes. The number
of supply sources (i.e., wells), the provision of auxiliary
power, and the provision of competent system operators were
important considerations inevaluating system reliability.
8.8.3 Imelementabi.lity
The potential for implementing the project is an important criteria
used to evaluate the .alternatives. Two issues related to project
implementation were considered:
Project scope--In-general, capital-intensive projects cover-
ing large geographic areas are more difficult to implement
than projects with a more limited geographic scope.
8-72
Public and political acceptability--Alternatives which in-
volve the transfer of water from one municipality to another
are more difficult to implement from a political standpoint.
This is due to potential conflicts in the development goals
of the two municipalities and to the complications that
arise from the need to involve additional government bodies
in the decision-making process. Alternatives which provide
needed service and meet local growth objectives would re-
ceive greatest public acceptability.
8.5.~ Environmental Considerations
The potential environmental consequences of the alternatives con-
sidered are:
(1)
Consumptive water use--This criteria considered the anti-
cipated consumptive use of water in each zone with respect
to the permissive sustained yield. Transfer of water from
one supply zone to another was a particularly importans con-
sideration, because such withdrawals are totally consumptive
from the perspective of the zone supplying the water.
(2)
Adherence to land use objectives--All alternatives were
designed to meet the land use objectives expressed in she
Comprehensive Plan. However, because of differences in
scope and the physical configuration of the supply and
transmission systems, the alternatives differ in their
potential for stimulating undesired growth. Therefore,
alternatives which minimized the potential for these nega-
tive "secondary impacts" were deemed more desirable.
(3)
Construction impacts--Water supply system components were
located, as far as practical, to minimize encroachment on
sensitive environmental areas. However, alternatives differ
in their impacts on these types of areas, particularly with
respect to stream crossings required for the construction of
major transmission lines.
8.5.5 Adaptability to Future Cha~ges
Depending upon the type and character of each alternative, some are
more flexible in responding to unforeseen future changes than others.
Those alternatives that require major initial construc~isn and imme-
diate financing tend to be tess flexible than those alternatives
which are gradually implemented over time. Because future conditions
in the study area cannot.be predicted with a high degree of cer-
tainty, adaptability of an alternative to future change is an aomir-
able, desirable characteristic.
8-73
5.5.6 Summary Comparative Matrices
Tables 8-24 through 8-29 compare all levels of alternatives which
were developed for each demand center on the basis of the five
screening criteria.
(121/5)
8-74
SECTION g.S
RECOMMENDED WATER SUPPLY PLAN
Section 8.0 of this report has presented in detail all of the water
supply alternatives studied and evaluated as part of this plan. Sec-
tion 8.0 also described the evaluation criteria and procedures used
to compare the alternatives. This section enumerates the water
supply alternatives recommended for implementation in each demand
center, Only brief descriptions of the recommended plans are pre-
sented--the reader is referred to Section 8.0 for the detailed
descriptions.
Table 9-1 summarizes the capital costs of the major structural com-
ponents of each recommended alternative. The table does not include
the capital costs for individual home treatment units since the
number of required units cannot be predicted. Section 8.0 of the
report, however, includes detailed capital and operation and mainten-
ance cost data for home treatment unit systems.
9.1 WADING RtVER/NORTHVIL~E
The Level III (B) alternative for Wading River/Northville, as shown
on Figure 8-6, is recommended for implementation. The existing in-
dividual water systems in Wading River, Baiting Hollow/Woodcliff Park
and Reeves Park should be connected to new supply wells, which will
separately serve each of the three individual subsystems. This is
necessary to improve the reliability of the supply and to assure
potable water. The new facilities should be located and sized to
al so serve areas which do not currently have public water systems;
the new service areas should be developed in a phased approach.
Table 9-1 includes the cost estimates to implement the Level
alternative. The future distribution ~ystem costs shown in the table
can be incurred over time as a town Water District oecomes finan-
cially able to provide public water service to those areas that are
presently unserved.
It is not economically feasible to provide public water systems to
the remainder of the demand center outside the service areas shown on
Figure 8-6. The residents in those areas should continue to oe
served by individual home wells, with trea~ent as required.
Schedule. The connections of the existing systems to new supply
~ould be accomplished wi thin a 3-year period. Service to new
systems along the route of the transmission mains should be accomp-
lished within 7 years thereafter, providing the areas are financially
capable of supporting the new facilities.
9.2 RIVERHEAD/jAMESPORT
The Level III alternative is recommended for the hamlet of Riverhead;
the only required m~or improvement is to increase distribution sys-
tem storage for the cost shown in Table 9-1. The Riverhead system
should also actively attempt to further expand its system to other
areas adjacent to the present system.
The Level iV alternative is recommended for the Calverton Area and
consists of extending the Riverhead system to serve the area shown on
Figure 8-7.
Jamesport and the remainder of the area in the demand center should
adoot the Level I alternative (i.e., continue to be served by indivi-
oual nome wells with treatment as reduired, since it is not economi-
cally feasible to serve those areas with public water facilities).
The capital cost estimate for the Riverhead/Jamesport recommendations
are included in Table 9-1.
jchedule. Additional distribution system storage and the extension
~iverhead system to Calverton should be accomplishd within a
3-year period.
9.3 MATTITUCK/CUCTHOGUE
The Town of Southold should acquire and 'operate the existing water
system in Mattituck Hills (Captain Kidd); measures should be taken
immediately to upgrade the performance and reliaDility of th~ system
and to augment its source of supply. In the remainder of the Matti-
tuck/Cutchogue demand center {including Cutchogbe, Mattituck, Little
Hog Neck, East Cutchogue, Fleets Neck, New Suffolk and Indian Neck)
i: is not economically feasible to provide public water supply sys-
tems. The Lqvel I alternative is recommended and these areas should
continue tO utilize indtv)dual home w~lls with treatment as required.
Table 9-1 includes capital cost estimates for implementing the
Mattituck/Cuthogue recommendations.
Schedule. The Captain Kidd acquisition should be completed within
6 mort:ns and system improvements provided within 1 year thereafter.
g.~ SOUTHOLD/GREENPORT
The Level III alternative as shown on Figure 8-13, is recommended for
Greenport. The Greenport Municipal System, which presently serves
Greenport and parts of Southold, should continue to rely on local
groundwater sources. However, major improvements to the system are
required. The existing Donohue Farm well should be upgraded to
~50-gallon-per-minute (gpm) total capacity and used for public water
supoly. A 2.2-million-gallon-per-day (mgd) reverse osmosis treatment
olant should be constructed in stages to treat the water from the
Donohue well and existing plants no. 6 and 7 for removal of nitrates,
pesticides, herbicides and salt.
After implementing the improvements, the Greenport system should
actively attempt to further expand its system to other areas adjacent
to the existing system.
in the remainder of the Greeport/Southold area, including Great Hog
Neck and East Marion, it is not economically feasible to provide pub-
lic water supply systems. These areas should follow a Level I ap-
proach and continue to be served by individual home wells, with
treatment as required.
Schedule. The upgrading of the Greenport system should be staged as
~as possible to minimize the impacts of the required capital
cost expenditures as shown in Table 9-t. The Great Pond feasibility
study should be undertaken and completed within 18 months. Concur-
rently, preliminary design efforts on the reverse osmosis plant
should be done. The Donohue Farm well and the final construction of
the reverse osmosis plant should be completed within 3 years. The
distribution system and storage additions should be implemented
within the next 5 to 10 years as the needs develop.
9.5 ORIENT
The Orient area, with its relQtively low density of development,
cannot economically support public water, so the Level I alternative
is recommended. Existing development should continue to be served by
individual home wells with treab~ent as required. Since the avail-
aDle fresh water supply is extremely limited, it is further recom-
mended that development in the Orient area be tightly contrblled to
conform with existi-ng zoning and result in water requirements which
are consistent with the permissive sustained yield o6 the aquifer in
Zone 5. It is further recommended that only variances resulting in
less water usage be apprbved.
9-4
~.~ ZSOLATED AREAS
Puolic water systems for existing isolated neighborhoods in areas of
~roundwater contamination are generally not economically feasible.
~herefore, it is recommended to implement Level I alternatives and to
continue to serve these areas by individual home wells wi th treatment
as required.
9.7 GROUNDWATER MANAGEMENT
Throughout this study and planning process, it was apparent that
groundwater contamination is extensive and, even if all contaminant
imputs to the groundwater were to immediately cease, the contamin-
ation will remain for many years. Because of the contamination,
numerous technical and financial problems associated with providing
water supply to areas of the North Fork were identifieq.
In order to protect the future groundwater quality and to reduce the
water supply problems associated with contamination, it is imperative
that preventive measures be taken in parallel with implementing the
structural components of this plan. At a minimum, the following
preventive measures should be considered:
(!) Expand the SCDHS observation well network and home well
sampling program.
(2)
Support the Cooperative Extension Service, Cornell University
and U.S. Department of Agriculture (USDA) research and educa-
tion programs directed to the home owner and farmer relative
to usage, dosages and timing of application of herbicides,
pesticides and fertilizers.
(3)
Support the testing of agricultural chemicals Dy State or
federal agencies in the local environment as a precondition
to use by the farm community.
(4)
(S)
Prohibit or control the sale or use of products and chemicals
which threaten the groundwater resources.
Control industrial, commercial and residential activities
whic~ impact negatively on groundwater quality.
{6} Incorporate detailed water quantity and quality considera-
tions into rezoning and variance decisions.
(7)
Encourage water conservation through public informacion pro-
grams and require water-saving fixtures in new home construc-
tion.
9-5
(8)
Continue public information and education programs to empha-
size the fragile nature of the area's water supply and to
foster cooperation in the solutions to those problems.
9-6
(SPH12/19)
SECTION 19.3
IMPLEMENTATION PLAN
!0.1 IMPLEMENTATION AGENCIES
A review was performed of institutional structures in order to select
an organizational framework under which the selected technical alter-
natives could be implemented. The objective of the institutional
analysis was to describe the entity that ~hould develop, finance,
construct, own and operate the required facilities.
Under the provisions of New York State Law, there are four institu-
tional entities that could be utilized to implement all or portions
of the selected alternative: the Village of Greenport, the towns,
the County or the Suffolk County Water Authority.
V~ll~ges (Village Law, Section 1.1-1102) are able to develop, own
ano operate a municipal water system, or to acquire an existing
system by purchase or eminent domain.
Towns (Town Law, Article 12-C) are able to develop, own and
operate a "water improvement," by resolution of the Town Board,
as a Town function servicing all or a particular area in the
Town; a permissive referend~ is not required under 12-C.
Towns (Town Law, Articles 12 and 12-A) and Counties (County Law,
~te S-A) can establish special improvement ~ricts, ini-
tiated.by resolution or by petition of the residents of the pro-
posed district, with the purposQ of developing, owning and oper-
ating a water system. The procedures for establishing such are
explicitly detailed in the respective sections of the State
statutes. Such procedures include allowances for a possible per-
missive referend;~n, requirements for stipulating the maximum
capital cost for district im_provements; identification of the
means of allocating costs within the district, and requirement of
State Comptroller approval of the proposed district.
Towns can also assume any or.all responsibilities for water
management as normal administrative functions. Thus, towns can
establish deparl~ments, groups, programs, etc. to coordinate water
development activities, ~onitor water qual'ity, pro~ioe-water-
testing services, provide informational services and generally
serve as the focus of water management activities.
!0 -1
Counties and Villages (General Municipal Law, Article Ia-C) may
develop, own and operate a water system as a revenue-prooucing
under.king. In addition to powers provided to such municipali-
ties in other statutes, this statute explicitly authorizes the
municipalities to develop water systems on a multi-municipal
level by resolution of the governing body of the particular muni-
cipality. Under such, no formal special district must be estab-
1 i shed.
The Suffolk County Water Authority was established under New York
State Law for the purpose or deve)oping, owning and operating a
water supply system.
Private water companies can also provide water supply services in New
York State.
The choice of an institutional structure for implementation should
always be dependent upon the alternative course of action selected
for implementation. The uniqueness of the recommended plan--a com-
bination of home treatment units and new and expanded municipal sys-
tems using local groundwater supplies--further limits the available
choices.
There is only one incorporated village in the study area, Greenport.
Since water quality problems exist throughout the two towns, and
townwide water supply actions are required, it is not possible for
Greenport to assume implementation responsibility except within its
own borders, unless it is contracted to do so by either of the towns.
The recommended technical alternative does not involve large, re-
gional systems or the transfer of water across municipal boundaries.
It focuses upon local sources of supply and control. Thus, there is
no incentive for the County to become involved. Additionally, Suf-
folk County government has historically left water supply responsibi-
lities to local units of government. Similarly, because of the local
nature of the recommended plan, it is inconsistent with the goals and
past involvements of the Suffolk County Water Authority. The Author-
ity has not shown an interest in implementing the type of plan recom-
mended in this report. The Authority might have difficulty financing
the plan since the Authority can only utitize revenue-bond financing
mechanisms. It is not clear that home treatment units, small water
systems for isolated neighborhoods and purchasing and interconnecting
small, private systems are amenable to complete revenue-bond finan-
cing procedures.
Clearly, governmental en~ities that should be responsible for imple-
mentation are the Towns of Riverhead and Southold. Water supply
districts may be established under Article 12 of Town Law (by peti-
tion of the people) or under Article 12-A of Town Law (by motion of
the Town 2oard). Water improvements can De established under Article
10-2
12-C. Water Management Programs can be estaolished as administrative
actions in the Towns. In all cases, the resultant entity can provide
%he full range of services contained in the recommended plan.
Under Article 12, a Water Supply District can be created upon receipt
of a petition signed by owners of taxable real property owning at
least one-half of the assessed valuation of real property. The dist-
rict cannot be extended into an incorporated village unless requested
by the village.
Under Article 12-A of Town Law, a town board may, by resolution,
establish a water supply district covering portions of the entire
town. The action is subject to permissive referendum if 5 percent of
the owners of taxable real property sign a petition asking for the
referendum. Again, the district may not be established or extended
into an incorporated village unless the village consents.
Article 12-C of Town Law authorizes a town board to provide for water
improvements as a town function in the entire area of the town (out-
side any villages) without the establishment of a district. The town
board is responsible for the management, maintenance, operation and
repair of the water supply facilities. The cost of providing water
improvments may be on a benefit or ad valormm basis. This oiffers
from Article 12 and 12-A, which provide that the expenses must be
charged on a benefit basis.
The cost of the water improvement can be borne:
- Entirely by the area of the town outside of any villages
- Partly by the area of the town outside of villages
- Partly by the lands benefited
- Entirely by the lands benefited.
The resolution adopted by the town board authorizing a water improve-
ment is subject to a permissive referendum only if all or any part of'
the costs are to be borne by the entire area---~Fthe town outside of
any villages.
Within the framework of the applicable laws as discussed above, the
following approach abbears to be the most desirable for the towns to
follow. The town governments should first create Water Management
Programs as administrative functions and appoint individuals to
direct the programs. These programs would assume responsibility for
managing and coordinating all of the water supply programs in the
townS.
10~3
As specific water supply needs develop, the program w~uld react to
solve them. If private water systems were to be taken over by the
town, for instance, the program would be responsible for organizing
the establishment of a new Water Supply District or expanding the
area of an existing district to purchase, own and operate the system.
A number of such districts could be created as private water com-
panies were taken over by the Town, or one Water Supply District
could be created to own and operate all the private systems. Simi-
larly, if new public systems were required, new districts could be
formed for Implementation.
Home treatment units could be handled as a separate town Water
Management Program function. A Home Treatment Unit District could be
formed covering all areas of the town not served by public systems.
Or, several Home Treatment Unit Distric--{-~' could be established in
specific areas where they are required, as they become necessary.
The Water Management Program and Home Trea~ent Unit Districts could
own and maintain the individual home treatment systems or could
create a set of regulations to allow private enterprise to do the
same. Under the latter approach, the'town should control which home
treatment units are to be allowed in .the town by retaining approval
power. In addition, the town should control maintenance by perform-
ing it themselves or contracting it to a private company under con-
trol of the town.
Schedule. Town Water Management Programs should be established imme-
~n both towns. Water Supply Districts for the ownership and
operation of new or existing public systems should be established
over a 1- to 5-year period, as the town Water Management Programs are
able to incorporate them. Home Treatment Unit Districts should be
established wi thin 1 year and begin providi'ng services at that time.
The number of home treatment units will increase over time; initial
emphasis should be focused on those ~reas where nitrate and pesticide
contamination is known to exist.
10.2 POTENTIAL FUNDING SOURCES
There are no State or federal grant programs from Fm~A or HUD cur-
rently avail able or funded to assist with the implementation of thi-s
study's recommendations. All funding, therefore, would have to be at
the local level.
There is a proposal for a New York State bond i~sue to Qss.ist local
munioipalities in funding ware6 systems but the timing, fat6 and
nature of the bond issDe are all unknowns at this ti~e.
If Riverhead and ~uthold.imolement this plan's 'recommendations,
financial support from a combination of ad valorem taxes ano benefit
charges and revenue-bond .financing'is appropriate. Thos~ costs in-
curred by the town Water Management Program w~ich benefit all town
residents (general management, sampling, wa~ar quality management)
could be paid for from the general tax base. Costs soecific to an
area (home treatment units, acquisition and operation of a private
water company) would be charged directly to the users; these types of
activities could be financed through revenue-bond issues.
10.3 LEGISLATIVE REQUIREMENTS
New legislation is not required to implement the recommendations of
this plan. There is some question as to whether or not home treat-
ment units can be considered as water supply facilities. An inter-
pretation by the legislature or State Comptroller would be helpful in
clarifying this issue.
(121/2)
t0-'5