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Ms. Lori Duncan <br /> October 26,2000 <br /> Page 3 of 3 <br /> contained benzene, toluene, or ethylbenzene, and no MTBE was detected in the 13 samples <br /> analyzed for that chemical (5 samples were in direct contact with groundwater). Only two soil <br /> samples contained any petroleum hydrocarbons: SBI-14.5' contained TPHG at 1.4 ppm and <br /> xylenes at 0.016 ppm, and SB5-14.5' contained 8.6 ppm TPHD. <br /> Given the documented south-southeast groundwater gradient, monitoring wells MW7 and MW8 <br /> (installed southeast and southwest, respectively, of the Yacht Harbor USTs) have provided <br /> information on water quality down-gradient and cross-gradient of the USTs. Available results from <br /> well MW7 (July 1990, three years after failed test at Yacht Harbor UST) were non-detect for <br /> TPHG, TPHD, benzene, and ethylbenzene, 0.73 ppb for toluene, and 2.0 ppb for xylenes. Results <br /> from well MW8 (October 1996) were 50 ppb TPHG, 1.9 ppb benzene, 8.6 ppb toluene, 1.5 ppb <br /> ethylbenzene, 5 ppb xylenes, and ND for TPHD. These wells are down-gradient(MW7) and cross- <br /> gradient (MW8) from the Yacht Harbor USTs and confirm that no significant groundwater <br /> contamination is due to the USTs. In fact, wells MW7 and MW8 represent the outer extent of the <br /> documented hydrocarbon plume resulting from former bulk storage operations located west <br /> (southwest to northwest)of the Yacht Harbor USTs. Both DTSC and the CRWQCB concluded that <br /> significant soil and groundwater contamination is present as a result of former bulk fuel operations <br /> at levels orders of magnitude greater than those found beneath the USTs closed in place at the <br /> subject site. Both agencies further concluded that an inferred source of contamination is located <br /> north and northwest of the former bulk storage facilities (cross-gradient to up-gradient from the <br /> subject site). Figure 1 (attached) shows the location of the USTs closed in place at the subject site <br /> relative to wells and borings installed to investigation contamination associated with the former bulk <br /> storage operatons. <br /> Based upon the evidence presented above, Ground Zero concludes that further investigation of the <br /> subject site would superfluous and is not warranted. Ground Zero, on behalf of the Waterfront <br /> Yacht Harbor, requests that PHS/EHD and the CRWQCB reconsider their request for additional <br /> investigation at this site. <br /> Respectfully, <br /> Ground Zero Analysis, Inc. <br /> John P. Lane <br /> CA Registered Geologist No. 6795 <br /> cc: Mr. Marty Hartzell, CRWQCB <br /> Mr. Lammert Van Laar,Esq. <br /> G:\Data\GRDONDZE\W aWrfr0nt\duncan I000.doc <br />