2. Pump #1:
Pump #1 is an electrically driven, vertical, well pump which can also be powered by a gasoline driven engine. The engine is under the administrative control of the Brentwood Water District. In order to activate the engine during a power failure, Brentwood Water must be notified to send a technician from the mainland. It is estimated that this will take a minimum of one hour. Although this pump has a larger flow capability, it is throttled to a maximum flow rate of approximately 275 gallons per minute (GPM), which is the maximum capability of the water treatment system, to provide proper treatment for health and safety of the public.

3. Pump #2:
Rump #2 is an electrically driven, vertical, well pump without any emergency backup. The pump is throttled to approximately 185 GPM for water treatment purposes.
Pump #2 is automatically activated when system demand cannot be maintained by Pump #1

4. Hydro-pneumatic Tank:
The water mains are pressurized by the use of compressed air in the hydro pneumatic tank. The 5000 gallon tank contains approximately 31000 litres of water with compressed air above the water level at a nominal pressure of 60 psi. The compressor is electrically powered without an emergency backup. During a power failure, the system will become depressurized when the water in the tank is expended.

Brentwood Water District will not permit the system to be operated at the capacities greater than the current throttling settings. If operated at larger flow rates, contamination of the system will occur, which will cause its shut down for potable water purposes until the entire system is flushed and drained.

5. Distribution Piping:
The distribution piping is constructed of transite [cement asbestos). The mains along Central Walk, portions of Bay Walk, and Broadway are six inch diameter (6") with branch lines of smaller diameter in varying sizes. Hydraulically speaking. a 6" diameter pipe has a maximum flaw capability of 500 to 600 GPM for standard design velocities and pressure drops. If, for instance, it was attempted to pump 1,000 GPM through a 8" pipe, the velocity would be 11.3 ft/sec with a pressure drop of approximately 6.0 psi per hundred feet of pipe. At a pumping rate of 1,000 GPM, the total pressure loss between Pump #1 and the eastern end of Dunewood would be 60 psi, which is the total pressure available. In layman's terms, this means that the maximum capacity of the system is approximately the capacity of the two throttled pumps (460 GPM).

6. Potable Water:
The system capability based upon pump settings and water treatment capability is approximately 460 GPM. Potable water use draws water from multiple locations with flow rates averaged out to the various mains and branches. Potable water is theoretically available for a maximum of 6 to 10 minutes in the event of a power failure. Experience has shown, however, that pressure is lost almost immediately in the entire system in the event of a power failure.

7. Water for Fire Protection:
During an electrical power failure situation, no water is available from the public water supply system in Fair Harbor.

Recent testing by the Fair Harbor Fire Department has demonstrated that when one pumper is connected to a hydrant and operated over 200 GPM, the system cannot meet this minimal demand after only a few minutes, and the suction lines draw a vacuum (become depressurized).

When two pumpers are connected to separate hydrants at remote locations, the system becomes depressurized almost immediately with almost total loss of fire fighting capability.

8. Interconnections:
The Fair Harbor water supply system is connected on the western side with the Saltaire system by means of a manually activated valve. On the eastern side, it is connected to the Suffolk water supply system also by a manually activated valve.

Since water from the Suffolk County system is also supplied by electrically driven pumps, water is not available in the event of a power failure from the eastern interconnect. The two wells in Saltaire do have emergency generator backup and can supply nominal amounts of water to Fair Harbor through the interconnect valve in the event of a power failure.

9. Conclusions:
The current public water supply system has limited potential to supply sufficient water for fire fighting purposes. Even with interconnection to adjacent systems [Saltaire on the western side and Suffolk County on the eastern side), the six inch diameter mains produce a pressure drop of approximately 2 psi per hundred feet of main at 500 GPM excluding pressure loss through fittings and valves. Thus, even with an interconnection open, the pressure and flows available are severely restricted (Estimated at 300 GPM total available). This was vividly demonstrated during the January 3, 1999 fire in Saltaire when only one pumper could operate efficiently although multiple pumpers were on the scene.

Based on the above, it is concluded that alternate water sources are required in order to provide adequate fire protection in Fair Harbor.

Informal discussion of the Fair Harbor Water System by
Neil Rudikoff, Fire Commissioner (10/1999)