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Corrective Action Plan Page 33 <br /> The air stripper instrumentation includes temperature (TI-1) and air pressure (PI-2) <br /> gauges An air pressure sensor (PS-2), wluch is connected to a low air pressure alarm <br /> (LPA-1), monitors the pressure of the air blown through the stripper If the air pressure <br /> sensor detects a low pressure condition, an alarm lamp mounted on the air stripper control <br /> panel is lit, the air blower is shut down and a signal is sent to the booster pump (P-2) <br /> f motor controller so that it is also de-energized and the flow of water to the air striper is <br /> stopped [Note Following such an upset, the air stnpper and booster pump remain shut <br /> down until the fault is diagnosed and corrected and the system manually restarted Under <br /> these conditions, if the groundwater recovery pumps (P-1) are operating, the water level <br /> in the surge tank will rise to the top of that vessel but overflow will be prevented by the <br /> action of the surge-tank high-level switch (LSH-1) which will de-energized the pumps in <br /> the wells j <br /> The air stripper discharge reservoir is emptied by a 1 1/2 horse-power, self-priming pump <br /> (P-3) which boosts the water to the upstream carbon adsorption units (GAC-1) The <br /> discharge pump is actuated by a controller (LC-2) connected to a water-level sensor (LS- <br /> 2) in the reservoir The discharge to that pump is automatically energized when water rises <br /> to within a preset level and de-energized when the reservoir is close to empty This <br /> controller also causes the air blower to be stopped after a delay of 15 min following the <br /> discharge reservoir being emptied A site tube (ST-1) permits the water level in the <br /> reservoir to be observed A valve (V-7) in the bottom of the reservoir permits the air <br /> stripper to be fully drained for maintenance <br /> If the air-stripper discharge pump fails and water threatens to overtop the discharge <br /> reservoir, that condition is detected by a high-level sensor (LSH -2) connected to a high <br /> level alarm/switch (LAH-2) which lights a lamp mounted on the air-stripper control panel <br /> When this alarm is activated, the air stripper blower is stopped (after a 15 rain delay) and <br /> a signal is also sent to the booster pump (P-2) motor to immediately de-energizes it and <br /> water flow from the surge tank (ST-1) into the air stripper ceases Overflow of the surge <br /> tank under this condition is prevented when water reaches the high level switch at the top <br /> of that vessel and the pumps (P-1) in the groundwater recovery wells are de-energized by <br /> the action of that device [Note Following such an upset, the groundwater pumps and the <br /> air striper remain shut down until the fault is diagnosed and corrected and the system <br /> manually restarted ] <br /> N-aise-control Enclosure Venting. The air stripper is constructed so that all gasses and <br /> fumes generated by the water aeration process are contained within the unit and eliminated <br /> through the exhaust stack However, as a precaution against any accumulation of fumes in <br /> the noise-control enclosure (NCE-1) that might occur if, for any reason, exhaust air <br /> escapes into it, the enclosure is ventilated by a fan (VFA-1) that is powered by an <br /> explosion proof motor Operation of the vent fan is controlled so that it is activated when <br /> the air stripper blower turns on and continues to operate for 10 minutes following the <br /> blower being turned off Fresh air enters the enclosure via a passive, louvered vent (AVL- <br /> 1) mounted in the wall of the enclosure <br /> r <br />