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HomeMy WebLinkAboutSewage Collection Treatment Plan of StudyTH~NRY .~IOUI'HIrR ENGINEERING CO. PLAN OF STUDY FISHERS ISLAND, N. Y. Prepared By THE HENRY SOUTHER ENGINEERING CO. BLOOMFIELD, CONN. 3une 1977 THai[NeY ~OUTHIrR ENGINEERING TABLE OF CONTENTS 1. FACILITY PLANNING AREA 1.1 Planning Area and Political 3urisdiotion 1.2 Entities that will Conduct the Planning 2. NATURE AND SCOPE OF THE PROBLEM 2.1 Exiet£ng System 2.2 Nature of the Problem TASKS, SCHEDULE, AND COSTS Paqe 1 5 6 7 8 Not ATTACHMENT: Engineering Report to Fishers Island Development Corp. THIIONRY ~OUTHER ENGINEERING CO. PLAN OF STUDY FISHERS ISLAND, N. Y. This Plan of Study is prepared subeequent to a meeting held with representatives of Federal and State Environmental Agencies, Fishera Ieland Development Corporation and The Henry Souther Engineering Co. It was decided at that meeting that the Plan of* Study would cover the entire island even though the only part that has a eewage collection system is the Fort Wright Area in the weetern end of the ialand. 1. FACILITY PLANNING AREA 1.1 Planning Area and Political 3urisdiction Fishers Island is located approximately three miles off the southern shore of Connecticut in Long Island Sound and is within the boundaries of the State.of New York. Its totaI area comprises about 75 square miies. The island serves primarily aa a summer resort area. However, some residences are ail year round. Fishers Isiand is a part of the Town of Southold. The centraI government is in Southold, LoI. The island is divided into two parts; One part is pubiicaliy owned with controi by the Town, of Southold, together with private homes in this area. Ali the municipai duties, such as maintenance of roads, are done by the Town of Southold in this area. The area inciudes the Fo~t Wright area, Hay Harbor and West Harbor, ail located in the western part of the island. A gate separates the eastern part of the isIand from the western part. The eastern part of the isIand is entirely privateiy owned and operated. The Town of Southoid does not - 2 - TH/~IFNRY SOLITH~rR IrNGINI'IeRING CO. provide any municipal services. However, the town has political jurisdiction over the eastern part of the island as well.~ The location of the 9ate is shown in Figure 1. Also shown in Figure 1 is the facility planning area, which is known as the Fort Wright area. The island In the exists population of the Fort Wright area and of the entire fluctuates considerably in the summer and winter months. Fort Wright area, where the only sewage collection system in the entire island, winter, or off-season, and summer, or peak season, populations are estimated to be about 180 and 350 respectively. For the entire island, the off-season and peak season population is estimated to be about 350 and 2,500 respec~ tively. Thesa figures were determined by counting the number of dwelling units and assuming.four persons per dwelling unit. The population in the island has not increased appreciably within the last ten years and it is anticipated that the population growth in the future will be rather slow, if any. As stated previously, the only sewage collection system in the i~land exists in the Fo~t Wright area. A map of the collec- tion system, showing pipe sizes and manholes, is given in Appendix ~. As shown in this map, pipe sizes range from 6-inch to 24-inch. There is no treatment facility. A 24-inch outfall pipe discharges raw sewage into Long Island Sound. The Henry Souther Engineering Company was retained to study the system and recommend a treatment facility that would provide at least a secondary treatment to the sewage before its discharge. A copy of the Engineering Report is ~*Appendi~ A is'given'at'the end of the Engin~erin~ Report THI SOU'[HER ~'NGINE~'RING CO. - 3 - given as an attachment to this Plan of Study. Further details of the existing distribution syatem can be obtained from this Engineering Report, particularly under the section titled "Existing Conditions." With the exception of the Fort Wright area, the rest of the residential units in the island utilize cesspools and septic tanks for on-site disposal of sewage. Seepage testa made through- out the island have indicated that the permeability of the soil is suitable for on-site subsurface disposal systems. For the eastern part of the island, where zonin9 regulations require building lots to be at least 2 acres or more, no sewage disposal problems should be expected with the soil types that are en- countered. In the western part of the island, that is to the west of the gate, the population is more concentrated. Even though the popu- lation is concentrated in the area between West Harbor and Hay Harbor, no problems with individual subsurface disposal systems have been reported or encountered. If any further aewering is to be cohsidered in the island,'the area between West Harbor and Hay Harbor would be the only logical area to be studied. The primary source of water supply in the island is Barlow Pond. This pond is located in the middle of the island and has always supplied sufficient water for most summer periods. There is a secondary source of supply in Middle Farms Pond. This pond is located to the east of Barlow Pond. Water is pumped from THI ~'NRY SOUTH£R ENGINEERING CO. - 4 - Middle Farms Pond into Barlow Pond when necessary. A portable pump is used for this purpose. There is aisc a well water sup- ply consisting of two deep weIls. However, these wells have never been used in the past. They are iocated by Middle Farms Pond. Water obtained from Bariow Pond is fiitered in a water treatment piant which has a capacity of about 0.5 mgd. This is' an old piant, constructed in i927. It consists of two filter beds, chiorination and pH adjustment. The fiitered water is pumped into 500,O00-galion elevated storage tanks where it is distributed to both the eastern and western parts of the island. A iO-inch pipe brings water from the storage tank into the area between West Harbor and Hay Harbor, and from this area a 6-inch pipe euppiies water to the Fort Wright area, or the facility pIanning area. The piping system for the island was etarted in the eariy 1900's. Consequentiy, the pipes are probably badiy corroded and tubercuiated as at times, low pressures are en- countered when the water use in the isiand is at its peak. Not all of the houses in the island, however, are supplied with fiit~red water. Some have their own individual well suppIies. As stated previousiy, the ieiand is mostly a summer resort ieiand although there are year-round residents. There is an association called "Fishers Island Civic Association," organized to"promote the economic, civic and social welfare of the island." This organization is trying "to keep an eye on all Iocal develop- ments and problems." NRY SOUTHER ENGINEERING CO. - 5 - Outside of the remains of the World War II fortifications in the western end of the island near Silver Eel Cove, there there are no historical sites or monuments that would be affected directly or indirectly by any development in the island. 1.2 Entities that will Conduct the Planning The Town of Southold is in the process of forming a Sewer District. This Oistrict will be in charge of sewage collection, treatment and disposal systems loc the facility planning area, which is the Fort Wright area. The personnel in charge of the District uill rsport directly to the Town 8oard. The Town 8oard, with its six members, is the 9overnin9 body in the Town of Southold. The six-Town 8oard members consist of one Supervisor, three Town 3ustices and two Councilmen.- The Supervisor will act as a representative for the Town Board in matters dealing with the grant appIication. The Town Board will authorize the Super- visor to do so on their behalf. The SuffoIk County Dept. of Environmentai Controi is the state agency having authority and jurisdiction on the quality of wastewater discharges in Fishers Island. In 1974, the State of New York Dept. of Environmental Conservation issued an Order to Fishers Island Development Corp. to "take ali the steps neces- sary for the instaliation of a sewage treatment system," and discontinue discharging untreated raw sewage into Long Island Sound. The raw sewage in question is the discharge from the' .existing collection system in the Fort Wright area. The fiIe number of this Order is 2005. Attached to this Order was a - 8 - TH~I;NRY gOUTHER ENGIN~rERING CO. compliance schedule setting a deadline for submission of an engineering report, final plans and specifications and comple- tion of construction; consequently, the cessation of discharge of all untreated wastewaters. This compliance schedule uae amended on February 3, 1975. Pursuant Order, Fishers Island Development Corp. Souther Engineering Co. to assist them to the receipt of this retained The Henry to comply with the terms of the Order. The Henry Southec Engineering Co. subsequently prepared an Engineering Report and submitted it to the Suffolk County DEC. This report quantifies the rates of sewage flows in the collection system service area and proposes a treatment scheme. Detailed description of the existing system and the proposed treatment scheme as well as the cost of construction of the proposed treatment system are given in the Engineering Report. 2. NATURE AND SCOPE OF THE PROBLEM 2.1 Existing System Description of major features of the existing collection systems is given in the Engineering Report presented as Attach- ment A. At the present time, there are two outfall pipes. The small outfall, which is to the north of Silver Eel Cove, is an 8-inch outfall, partially broken, and the 24-inch outfall where the location of the proposed. The small outfall structure is major outfall is a treatment facility is proposed to be abandoned and the wastewater in this area pumped into the collection system leading to the proposed treatment facility. - ? - T~IENRY SOUTHER ENGINEEFIING 2.2 Nature of the Problem The sewage collection system is an old system, collecting sewage from a totally residential area (no commercial or in- dustrial establishments exist) and discharges, without any treatment, into Long Island Sound. Laboratory tests on samples collected from the outfall pipe indicate high 8OD, suspended solids and coliform organism count. The problem, therefore, is to provide at leaet a secondary treatment to the sewage before it is discharged into the raw sewage into the Sound concern. Sound. The existing discharge of is the cause of serious environmental - 8 - 3. TASKS, SCHEDULE, AND COSTS Preparation of the Facility Plan will entail tasks: Effort Task (Man-Weeks) 1. Effluent Limitations (to be provided by the State) 2. Assess Current Situation a. Evaluate existing system (Optimum Performance) b. Planning Area Description c. Demographic and Economic Data d. Water Quality Data e. Environmental Inventory (including cultural resources) f. Infiltration/Inflow Analysis lO Assess Future Situation a. Future environment with "No Action" b. Land Uss Projections Co Demographic and Economic Projections d. Flow and Wasteload' Forecasts (8asis for Industrial Flow Forecasts) Develop and Evaluate Alternatives a. Alternative 8PWTT Waste Management Techniques (Expanding and Upgrading Exist- in9 System, Regional Solutions, Alternative Treatment Sizes and Configurations, Alternative Residual Waste Management Techniques; Environmental Effects) b. Public Participation 6 Select Plan~ a. Public Meetings and Hearings b. Environmental Impacts of Selected Plan c. Summary of Public Participation the following Schedule Costs 3,000 300 350 800 400 6,000 1,200 500 500 1,000 6,000 1,200 600 1,200 600 1 2 3 4 5 6 7 Months - g - TASKS, SCHEDULE, AND COSTS (CONT'D) Task Effort (Man-Weeks) Schedule Preliminary Design of Selected Treatment Works a. Full Process Design Layout, Design Criteria, Sizing, Loading Rates, Detention Times b. Detailed Cost Estimates (Design, Construction, and Operatson & Maintenance) 1 Implementation Arrangements a. Institutional and Legal Requirements b. Preliminary Operation & Maintenance Plan c. Non-Federal Costs, User Charges and Debt-Service Charges d. Financial Arran9ements to meet Non-Federal Costs e, Resolutions of Pian Acceptance 2 Archaelogical Survey Report Preparation and Printing Costs 1,200 1,200 '1,200 2,400 6O0 2,400 $32,650 1 2 3 4 5 5 ? Months FACILITIES PLANNING AREA ("FORT WRIGHT AREA") 18 GATE 30 ' 30 /5' 12. 6 IZ FIG FISHERS ISLAND,N Y FACILITIES PLANNING AREA SCALE I"=1000' THE NENRY $OUTHER ENGINEER~NC= CO. 24TOBE¥ RD BLOOMFIELD CT. 0(,005