ARCHIVED REPORTS XR0012287 - Laserfiche WebLink

Home Browse Search

March 18, 1993 Page 5 Conceptual Site Model s [ i� � p #�ccurred on a piping run located on site y . z pod, Product release notification procedures are'relatively new mandates. It is also possible that petroleum hydrocarbons may have entered the subsurface environment via product transfer operations and There was no information disclosed to suggest there was any other significant release. Since loading and off-loading procedures have become more stringent, and technological advances have allowed for better equipment and product reconciliation tracking, PACIFIC suggests that there are no longer any primary sources of petroleum hydrocarbons at the site. The greatest hydrocarbon concentrations were detected in soils within the 5- to 6- 1/2-foot interval in Wells U-1 and U-2 and in the 7-to 8-1/2-foot interval in Boring U-C. To a lesser degree Well U-5 and Boring U-A were impacted. Thus the major impact area appears to be in the vicinity of the aboveground bulk tanks, loaders, and loading rack, above the piezometric surface. Q71PP06i4a n is 1 �jgZEp,, amles takenform >w o ated downp�radient frQM4 Impacted soil beneath the site has been characterized primarily as clay, and stratig- raphy within the impact zone does not appear to be complex. The gradient beneath the site seems to be consistent with the regional flow direction; north to northwest. Geological cross-sections are presented as Figures 3 and 4. Of foremost health and environmental concern are BTEX compounds; constituents of gasoline. These compounds have been identified in groundwater beneath the site at concentrations exceeding primary and proposed secondary Maximum Contaminant Levels (MCLS) for drinking water per Title 26, Division 22, Section(64444.5) of the California Code of Regulations (CCR). As previously stated, groundwater beneath the site is considered a potential source of municipal and domestic drinking water supply. r � ttia radius o t -'O t -siteJS and WSW- = z 3100104/1RAP