ARCHIVED REPORTS XR0003037 - Laserfiche WebLink

Home Browse Search

Chevron Products Company 4 Former Chevron Service Station #9-5775, 301 West Kettleman lane, Lodi, California June 5, 2001 detectable concentrations of hydrocarbons or fuel oxygenates have been reported in this well (City of Lodi and G -R) SECOR, Final Remediation Plan (August 25 2000. SECOR proposed the continual operation of the GWE and SVE systems with the addition of one GWE well (MW-14/EX-2) SECOR, A ui er Test Report arch 30 20011, Between November 13 and 27, 2000, SECOR conducted an aquifer test to estimate various aquifer parameters Based on this, the average transmissivity (T) and storativity (S) values that were determined from aquifer pump test activities were approximately 1,497 ft /day and 0 1, respectively. Assuming a saturated aquifer thickness of 445 feet, hydraulic conductivity of the aquifer is approximately 3 5 ft/day Results of the aquifer test are discussed in further detail in section 5.11 2.2 Quarterly Monitoring Data The following discussion provides a brief summary of hydrocarbon constituents in groundwater While numerous petroleum hydrocarbons and fuel oxygenates have been identified in on-site and off-site wells, the primary constituents of concern have been identified as TPHg, benzene, and MtBE A more complete description of the constituents identified in groundwater beneath the site can be found within Attachment D Quarterly groundwater monitoring and sampling of monitoring wells was initiated in January of 2000, and is currently ongoing Historical monitoring data from site wells indicate that depth to 40 groundwater at this site has been measured between 54 to 59 feet bgs (Table 3) Groundwater flow has generally been reported to the southwest, at an approximate gradient of 0 003. Figure 3 depicts the locations of former site facilities (including the USTs, dispenser islands, and station building) in relation to on-site and off-site monitoring and extraction wells • Historically, TPHg has been reported in on-site A and B -zone wells primarily located in the central and south -southwestern portions of the site at a maximum concentration of 68,000 ug/l (EX -1) During the first quarter 2001, TPHg was reported in two A -zone monitoring wells located to the west (MW -3) and east (MW -4) of the former USTs at a maximum concentration of 980 ug/l (MW - 3). TPHg has not been reported in off-site monstoring wells Historically, benzene has been reported in on-site A and B -zone wells primarily located in the vicinity of the former USTs at a maximum concentration of 39,000 ug/l (EX -1) During the first quarter 2001 sampling event, benzene was reported in three A -zone wells located to the west (MW -3), east (MW -4) and northeast (MW -11A) of the former USTs at concentrations ranging from 0 52 ug/l (MW -11A) to 380 ug/1(MW-3) During the most recent sampling event, benzene was reported in B -Zone well MW -5B (located southwest of the former USTs) at a concentration of 0 59 ug/l. Historically, MtBE has been reported in on-site and off-site A, B, and C -Zone monitoring wells at concentrations ranging from 0 63 ug/l (MW -8A) to 720,000 ug/l (EX -1) During the most recent I \Chevron1957751ParFrpl9.5775PARFRP2 doc