Laserfiche WebLink
1 <br /> C,edlogical ?ecknics lfic. <br /> ' 1101 7`h street <br /> Modesto,Califorma 95354 <br /> (209)522-41191Fax(209)522-4227 <br /> REPORT <br /> Groundwater Monitoring <br /> 1 40' Quarter 2004 <br /> Valentine (Castle Motors) <br /> 2315 N. El Dorado St. <br />' Stockton, CA <br /> Project No 723 2 <br />' February 28, 2005 <br /> EXECUTIVE SUMMARY <br /> This report summarizes the 4'h Quarter 2004 round of groundwater monitoring and testing <br /> that took place on October 21, 2004 <br />' The laboratory results indicate that detectable concentrations of the aromatic hydrocarbon <br /> compounds (BTEX) and gasoline range petroleum hydrocarbons (TPH-G) are present in all <br /> six shallow/intermediate monitoring wells on site On site deep well MW-101 intermittently <br />' contains contaminants and it contained low levels of BTEX and TPH-G for the event Deep <br /> well MW-201 contained trace BTEX (0 4 — 10 ug/1) contamination which GTI believes is a <br /> drilling artifact It dad not contain contamination for the previous three 2004 sampling <br />' events <br /> The first detection of TPH-G in cross gradient well set MW-207 probably represents the edge <br /> of the advancing plume The well did not contain contaminant concentrations above the <br /> laboratory reporting limits for the three previous 2004 monitoring events The intermediate <br /> and deep intervals of the up gradient well set MW-91109/209 contained trace BTEX (0 4 — <br />' 10 ug/1) This may represent the up gradient edge of the plume or a remnant of some up <br /> gradient off site contamination <br />' The groundwater elevation averaged —29 49 feet mean sea level in the wells and this <br /> corresponds to about 40 feet below grade surface (bgs) This elevation is a decrease of <br /> approximately 2 06 feet since the August 8, 2004 monitoring event Groundwater gradient <br /> 1 <br />