ARCHIVED REPORTS_XR0012628 - Laserfiche WebLink

Home Browse Search

i r � . WALLACE •KUHL&ASSOCIATES,INC. June 19, 1990 San Joaquin County Environmental Health Division Attention: Eleanor Ratliff P.O. Box 2009 Stockton, California 95201 -- SOIL BORING REPORT L4THROP PROPERTY 91 E. Thomsen Road Lathrop, California WKA No. 1184.02 We performed a Preacquisition Site Assessment of the subject property in April, 1990. Our • initial work revealed that the property had at one time been an automobile service station; aerial photographs indicate the service station was removed by 1975, We understand the underground storage tanks were removed in the 1970s. . Our site assessment included an exploratory soils boring program in an effort to Investigate subsurface soils for potential petroleum contamination resulting from underground fuel tank leakage. Boring locations are shown on Plate 1. Soil borings were accomplished with a Mobile 853 truck-mounted drill-rig equipped with hollow- stem augers. Borings were six inches in diameter and drilled to a maximum depth of 15 feet below existing site grade. Soils samples were obtained at maximum five-foot intervals within the borings using a modified California sampler containing clean brass tubes. The sampler was driven by a standard 140-pound hammer freely falling 30 Inches. All sample tubes were sealed with aluminum foil, plastic end caps and tape, and preserved on ice; two soil samples were submitted under chain-of-custody to a California-certified analytical laboratory for analysis of total petroleum hydrocarbons (EPA method 8015 modified), and benzene, toluene, xylene and ethyl benzene (EPA method 8020). Field readings of potential contaminant concentrations were obtained with an organic vapor analyzer (OVA). Complete descriptions of materials encountered during drilling, boring depths and OVA readings are included in the boring logs on Plates 2 through 6.