Laserfiche WebLink
1 the supply wells also failed to reveal contamination at levels <br /> 2 warranting further investigation. One well had only .0008 ppm „/'f <br /> 3 toluene, .37 ppm TPH diesel and .0004 ppm benzene. V <br /> 4 Concentrations of petroleum hydrocarbons in the other wells were <br /> 5 lower or non-detect. .Based on this data, SG&D recommended and <br /> 6 Petitioner requested case closure. <br /> 7 The Health Department, however, was not satisfied with the <br /> 8 data and demanded additional work as a condition to case closure. <br /> 9 The second round of sampling, which took place during the week of <br /> 10 October 8, 1990, involved the drilling of four soil borings to <br /> 11 depths of 90 feet below grade and installation of monitoring well <br /> 12 MW-1, in order to assess the presence of TPH diesel, benzene, <br /> 13 toluene, ethyl benzene and total xylenes in deeper soils and in <br /> 14 the groundwater beneath the UST. These sample data indicated ,.- <br /> 15 that no contamination had migrated to groundwater. Again, S0&D <br /> 16 recommended that no further action be taken and, based on their <br /> 17 advice:, Petitioner requested case closure. <br /> 18 Again, the Health Department denied Petitioner's request <br /> 19 and demanded more data. On May 22, 1991 Petitioner resampied the <br /> 20 groundwater monitoring well below the former UST. This sample <br /> 2`1 was collected at approximately 75 feet and revealed only trace <br /> 22 amounts of toluene ( .0006 ppx) , which were several hundreds of <br /> 23 times lower than the action level of 0. 1 ppm. No other <br /> 24 contaminants were detected. <br /> 25 The Health Department was still unwilling to close the <br /> 26 case, and in 1993 issued its Order, directing Petitioner to <br /> 27 submit a work plan providing for (1) the investigation of the <br /> 28 vertical extent of the contamination in the tank excavation, <br /> -3- H\VMCIC0L0RSPTUPPEAL.PL4(5P2) <br />