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01 May 2007 AGE-NC Project No. 07-1516 Page 36 of 39 r_ • A Former Discharge Area Investigation Report was performed by Weston, Inc. and dated �. 29 August 1989. The recommendations from the 1989 Weston report noted that since soils were predominately fine textured and laterally contiguous and that the ground water yield was very limited, the soil had low permeability and transmissivity. These hydraulic conditions,coupled with the known low mobility of organochlorine pesticides found in soil, suggested that the migration of perticide and herbicide compounds through the soil was unlikely. It was recommended that an annual ground water monitoring program be initiated utilizing the three existing monitoring wells and that the wells should be sampled for organochlorine and carbamate pesticides. The monitoring program would ensure that no significant chemical migration occurred and would serve as a routine assessment of site conditions. No further remedial actions were recommended, noting that remediation costs would over-weigh any benefit gained by the removal of the low-residue soil. bw 0 The CVRWQCB accepted the Weston recommendations and noted that due to low levels of pesticides and herbicides found in soil,no further soil remediation or removal was required. be The CVRWQCB instituted ground water monitoring in 1990; after two monitoring events in 1991, the CVRWQCB stated that the monitoring requirements for the property were completed. • A large amount of hazardous materials, including drums of oil and waste oil, paints, pesticides and other containers was stored inside the metal hangar,usually on pallets. Some 'u staining of the dirt flooring was noted. • A Site Inspection Report prepared by URS Consultants and dated 26 May 1992 noted in addition to known contaminant areas that a chemical batch unit and holding tank were located outside the office/shop/hangar,engine oil maintenance was performed on the airplane parking strip, chemical/barrel storage areas were located east from the parking strip and adjacent to the metal hanger, two empty USTs were located on the property, one (aviation gasoline) within the airplane parking strip and one east from the southern hangar and that four ASTs were located on the property, three stored from a nearby former service station and one used to hold fuel when the USTs were emptied. AGE notes that the UST near the parking strip was removed in 1992 and is a closed case and has no information concerning either the UST near the metal hangar or the four ASTs. �,. Three 6,000-gallon USTs(two aviation fuel one unleaded gasoline)were removed from the site in June 1989 without SJCEHD permits.AGE has no direct knowledge that investigations of the tank pit area have been performed;the UST location appears to have been northwest ■a from the now-demolished hangar/office building, but this is not certain. A SJCEHD permit worksheet from 1990 shows three 6,000-gallon USTs,but no removal documentation. Ir Advanced GeoEnvironmental,Inc.