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i Dissolved oxygen levels were recorded this quarter at this site The levels were measured with a calibrated YSI model 51 B meter by placing the sensor 5 feet below the surface of the water table after the bailing of the wells The measured levels are shown on Table 3A The readings of dissolved oxygen are between 1 1 at well BM-8 and 7 5 at well BM-7 The oxygen level in BM-7 has been high since we introduced Oxygen Release Compound (ORC) into this well in July 1997 The oxygen level has been falling about 0 6 milligram/ liter each quarter since the ORC was removed in July 1998 I VAPOR EXTRACTION SYSTEM The site has been under remediation since July 1997 The weekly readings of the entering vapor stream are listed on Table 5 and shown on Figure 5 The vapor contamination level remained the same this quarter A total of 42,549 pounds of gasoline has been removed since the beginning of this project On January 27, 1999, we had the input and discharge gases analyzed The results are shown In Table 6 and the laboratory report is attached The findings of the laboratory showed that no BTEX chemicals were entering the system The only time we would expect BTEX chemicals to be present is through the sparging operation we are planning to construct or if the water table falls below its present level Both of these possibilities are probable in the spring of this year We have shut off the Vapor Extractor System for the time being Conclusions We will continue to monitor this site The next monitoring event will take place in April 1999 We have received approval from the EHS on January 22, 1999 for the drilling of two wells one for water and the other for vapor extraction The plan to commence this operation in March 1999 Yours truly D GL p�v John Cussentk CUs��2�� RG #6506 No.6" Enclosures 6 TablesgP 5 Figures SOF CAI.I� I 3 Laboratory Reports and Chain of Custody's 11 Sample Sheets !� Cc Mr Roger Liston, Darpetro, Inc " Mr G L Boggs, RWQCB