ARCHIVED REPORTS_XR0003889 - Laserfiche WebLink

Home Browse Search

i Each well was purged before collecting water samples. Purging was completed only after water temperature, pH, and conductivity had stabilized. Purged water was contained in a labeled, secured 55 gallon drum on site . This purged water and some additional waste rinse water that had been produced during the drilling of MW8 on February 8 , 1993 (a total of three 55 gallon drums) has been transported to the USA refinery in Ventura, California for recycling Transportation arrangements for the waste water were made by USA Gasoline Corporation The wells were allowed to recover after purging A water sample was then collected with a fresh bailer Each sample was divided among four 40-m1 VOA vials The vials are supplied by the laboratory or a chemical supply company and are pre-cleaned to exact EPA protocols The sample vials were labeled as to station, well, time, and sampler, and documented on the chain-of- custody sheet, they were then placed into an ice chest and cooled to 40C with ice The samples were delivered to a California State Certified Laboratory and signed over to the lab using standard chain-of-custody procedures Field notes describing the collection of water samples are included in Appendix A. Chemical Analysis Results The water samples were analyzed at Matrix Environmental Laboratories (DHS #1676) for Total Fuel Hydrocarbons (gasoline) with BTEX distinction, utilizing EPA Methods 5030 and 602, respectively. The analytical results from these water samples (MW3 , MW4, MW6, and MW8) were all Below Reportable Limits (BRL) except MW8 which indicated low levels of TFH { 28 ppm) and Benzene (130 ppb) The current localized impact of TFH-gasoline and benzene on ground water is depicted in Figures 5C and 6C The analytical results and pertinent reference data are listed in Table 1 Matrix' s laboratory report is included as Appendix B DISCUSSION OF RESULTS The ground water data obtained during the current monitoring round show no significant changes since the last quarterly monitoring report Ground water flow direction 3s to the south- southeast with an average gradient of 0 006 feet per linear foot Ground water at the site is currently in a discharge cycle Previous discharge and recharge cycles at the site have produced sporadic traces of TFH or BTEX constituents in some of the 4 i