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Third Quarter 2000 Site Update - Former Chbvron 99-5775 (CAO #5-00-704)
<br />October 12. 2000
<br />hydrocarbons in the MidPointl, MidPomt2 or Effluent samples, however, the carbon had already been
<br />changed out The system was not shut down during carbon changeout
<br />A very low concentration of xylenes was detected in the Effluent sample collected August 10, 2000 The
<br />system was shut down on August 11, 2000 Confirming samples were collected August 16 and August 18,
<br />2000 The samples collected from MidPointl, MidPoint2 and Effluent contained petroleum hydrocarbons
<br />The laboratory noted that compounds reported at TPHg were due almost exclusively to the presence of 2-
<br />butanone and tetrahydrofuran It is believed these compounds came from the glue used to construct the
<br />GWS Approximately 1,500 gallons of tap water was flushed through the system and discharged to a holding
<br />tank The system was placed back into operation on August 18, 2000 The GWS did not pump groundwater
<br />from August 11 to August 18, 2000
<br />During the sampling event of September 6, 2000, the system was down for approximately 1 hour while the
<br />pump and probes in well EX -I were cleaned and the level switches were reset
<br />Approval from the CVRWQCB to Secor International for the GWS included pumping from wells EX -1 and
<br />MW -14 Initial attempts to pump from well MW -14 produced mud and sand, so the well was not initially
<br />connected to the system This well was re -developed and brought online September 22, 2000 Due to the
<br />extra influent from MW -14 and what is believed to be an air bubble trapped in the feed pump, the system
<br />shut down automatically at approximately 1 00 am on September 26, 2000, due to high water level in the
<br />surge tank The feed pump rate was adjusted and the system brought back on line at approximately 10 15
<br />40 am the same day
<br />In an effort to increase the discharge rate from well EX -1, GR re -developed the well on September 27, 2000
<br />The well was mechanically surged with a 4-mch diameter bailer Well EX -1 was off-line from
<br />approximately 9 00 to 9 45 am on September 27
<br />Summary of Well Pump Operations
<br />Wel l EX -1 pumped throughout the quarter Based on data collected September 20 and September 27, 2000,
<br />this well pumped 535 gallons of groundwater, with a calculated discharge rate of 0 06 gallons per minute
<br />(gpm) However, well EX -1 was re -developed on September 27, and future flow rates from this well may
<br />be higher The sample collected from this well on September 27 contained 200,000 ppb of MtBE, 9,700 ppb
<br />of tert-butyl alcohol (TBA), 6,400 ppb of ethyl tert-butyl ether (ETBE) and 2,200 ppb of tert-amyl methy l
<br />ether (TAME) This sample did not contain detectable concentrations of TPHg, BTEX compounds, di -
<br />isopropyl ether (DIPS), ethanol, methanol, 1,2-dichloroethane (1,2 -DCA) or ethylene dibromide (EDB)
<br />During this period well EX -1 removed approximately 0 22 lb of TPHg, 0 002 lb of benzene and 0 89 lb of
<br />MtBE
<br />Pumping from well MW -14 began on September 22, 2000 Between September 22 and September 27, well
<br />MW -14 pumped 1,400 gallons of groundwater at a calculated rate of 0 20 gpm The sample collected from
<br />this well on September 27 contained 790 ppb of TPHg, 3,000 ppb of MtBE, 87 ppb of TBA, 320 ppb of
<br />ETBE and 40 ppb of TAME This sample did not contain detectable concentrations of BTEX compounds,
<br />. DIPE, ethanol, methanol, 1,2 -DCA or EDB During this period well MW -14 removed approximately 0 03
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