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Page 6 of 14 <br /> Subject: RE: 76 #5886 <br /> Ben, <br /> my work continues on this site from ----, <br /> I have another obstacle. <br /> as some background, the SWRCB and the CVRWQCB have <br /> standardized approaches at 'comparing' / 'evaluating' effectiveness of a <br /> corrective action at a LUST site preparing for NFA. One way is a <br /> generalized "BEFORE REMEDIATION" soil and gw versus an "AFTER <br /> REMEDIATION" soil and gw comparison. supports a trend when the <br /> after is way lower than the before... <br /> Typically, the initial UST system removal (USTs, piping, dispensors) or <br /> preUST removal soil boring data provides the "BEFORE" data. You can <br /> see how this data would typically be elevated since no clean up done. <br /> No surprise that this data provides some of the highest levels on the <br /> site. <br /> then additional borings and MWs are placed as part of the required <br /> investigation. We see more soil and gw data. then, most sites go into <br /> remediation, and this site is no exception. After remediation is <br /> completed, the MWs provide gw data for the "AFTER". Trends show up <br /> here over years of gw sampling.. not a problem for this site....but my <br /> problem is the "AFTER" for soil. I can't find any soil data after 1997. <br /> Some of the hottest soil hits for this site were from 1995 piping and <br /> dispenser samples. No surprise. and they were all collected in the <br /> island/center of the site as compared to the UST pit to the east. <br /> trouble is, NO borings other than the 1997 hand augers "HA-1" to "HA- <br /> 3" were collected in this central area since. <br /> HA-3 reports the HIGHEST MtBE in the soil for the site. Not much at 12 <br /> mg/kg, but we typically try to get data later on to support even this level <br /> has been 'cleaned up'. And TPHg & TPHd d soil data are highest in the <br /> "D" and "T" borings from 1995. <br /> and NO MW or AS well has been installed close enough to these points <br /> to provide serious support for conclusions that the soil has cleaned up. <br /> Look at it like a regulator. 1995 first and HOTTEST soil hits, but NO <br /> MtBE analysis. then a dig out after this and a hand auger after the dig <br /> out reports the first and hottest MtBE in shallow soil over very shallow <br /> gw. "HA" hand augers installed AFTER the canopy supports were <br /> dugout in 1995 data have no current comparisons or soil data within 50 <br /> feet of HA-3's location. <br /> NO 'after remediation" MtBE soil data appears available for this area. <br /> am I wrong? <br /> 3/14/2011 <br />