WORK PLANS - Laserfiche WebLink

Home Browse Search

4. 5.0 CONCLUSIONS AND RECOMMENDATIONS The following-conclusions and recommendations are presented in this report. 1) BTEX components were not detected in the June 1994 groundwater samples whereas they were detected at component concentrations ranging from 0.84 ug/l to 20 ug/l in the June 1993 sampling event. { 2) TPH/G has never been detected in the groundwater samples collected at the Site. hr 3) TPH/D concentrations decreased in wells MW-2 and MW-4 between June 1993 and June 1994;however,the TPH/D concentration increased from non-detectable in MW=1 to 1,700 ug/l, which is considered to be a relatively low level. 4) Free product has been removed from well MW-3 using a passive recovery device since May 1994. The amount of free .product removed from the well has been decreasing; however, it is not clear as to whether this is due to the presence of less free product, a lower water level,and/or non-optimum depth placement of the recovery device within the well. The placement of the device in the well will be checked, free product will continue to be removed at least weekly, and SECOR will review:the free product recovery results on a monthly basis. 5) The soil sample analytical results from well MW=3 were inconclusive as to the depth from which free product is emanating. These results are considered.to be.qualitative since the samples collected from depths below.5 feet had exceeded their holding times. TPH/D was detected at 85 mg/kg in the sample collected from a depth of 5 feet and at 64 mg/kg.from the sample collected from a depth of 15 feet. 6) Since naturally occurring biodegradation appears to have -.reduced groundwater concentrations, additional investigation and/or remediation, beyond the removal of free product from MW-3, is not recommended at this time. The Quarterly Monitoring and Reporting Program will be implemented upon Regional Board finalization. CC l� G:\SUSAN\TOWERPK\WKPLAN 50114-001-01 5-1