operation, maintenance and monitoring plan ... - Ithaca-SHIP.org!

a low profile tray air stripper equipped with a sump, discharge pump, and blower. The air stripper sump
is outfitted with a series of high and low level switches that will actuate the Gould’s NPE 1 st 1ST1F5D4 1-
1/2 hp effluent transfer pump, the American Fan Company cast aluminum pressure blower, and provide
shutdown capability in case of malfunction. In addition, if the blower shuts down or malfunctions, the
system will discontinue operation.
After treatment by the low profile tray air stripper, the water is pumped through two 250-pound liquid
phase granular activated carbon (GAC) units. The carbon units are outfitted with pressure indicators
before and after each unit to monitor pressure buildup. In addition, sample ports are located before and
after each unit.
The treated effluent is then discharged via a 4-inch OD pipe to the existing State Pollution Discharge
Elimination System (SPDES) discharge Outfall #001 located along the footpath in accordance with the
SPDES permit.
2.1.3 Vapor Stream Treatment Equipment
Vapor is removed from each extraction well by the application of a vacuum to the wellhead. Extracted
vapor is conveyed via HDPE pipe into the treatment building. The vapor stream enters a 120-gallon
air/water separator to facilitate separation of moisture from the vapor stream. Liquids removed from the
vapor stream are conveyed by a Moyno 35601 progressive cavity transfer pump to the equalization tank
for aqueous treatment. The air/water separator is outfitted with a series of high and low level switches
and alarms wired to the PLC that actuate the transfer pump or shutdown the system in case of
malfunction.
Vapors are conveyed by a Sutorbilt Legend ® (model 5LP-DSL) positive displacement rotary lobe blower
with 20 HP Emerson motor. The blower is capable of producing 300 scfm at 10 inches of mercury (Hg) at
the blower inlet. Air flow and vacuum transmitters, sample ports, and pressure and vacuum gauges are
installed on the separator and blower unit piping to allow for proper operation of the system. The blower
is wired to shut off in case of high pressure or vacuum in the air line. Vacuum relief valves are located at
the inlet of the vacuum blower and at each wellhead to set the design system vacuum and to prevent
excessive vacuum if air flow is not present at a specific wellhead. The flow and vacuum at each wellhead
will be determined in the field during operation of the system.
The recovered vapor stream is treated by two 1,000-pound vessels of vapor phase GAC in series before
entering a Universal Silencer (model RD-8) exhaust silencer and exiting the building via a discharge
stack to the atmosphere. In addition to the recovered vapor stream, the air stripper effluent vapor stream
tees into the recovered vapor stream prior to the GAC vessels.
2.1.4 Process Logic Control, Automated Equipment Actuations and Alarms
Automatic actuation of the remedial system equipment is achieved using a PLC-based system control
panel with a web-based telemetry controller. The PLC will automatically turn off the entire system in the
event of certain predefined alarm conditions and notify WSP Engineering personnel immediately by email
via a mobile device. The PLC also features remote interface and emergency stop capabilities from
designated stations controlled by WSP Engineering personnel.
Two sets of water level sensors are used to actuate the equipment during normal operation of the
treatment system. As discussed above, a level switch high (LSH) is activated within the equalization tank
once the water level within the tank rises to a predefined level. The activation signal causes the PLC to
power the first water transfer pump and convey water to the filtration bag units, air stripper, and GAC
units for treatment. Once the water level has been lowered, triggering the second switch, level switch low
(LSL), the PLC is signaled to turn the transfer pump off. Once the LSL is reached the PLC sets the air
stripper blower on a 15-minute cycle to allow adequate treatment time of water already past the first
water transfer pump. A similar set of water level switches are also installed on the low profile air stripper
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