COMPLIANCE INFO - Laserfiche WebLink

Home Browse Search

Tetra Tech EMI Inc. 10670 White Rock Road,Suite 100 • Rancho Cordova,CA 95670 • (916) 852-8300 • FAX (916) 852-0307 May 6, 2004 1�_ I� (� UZlL� �'1' D Mr.John Compaglia MAY 0 7 2004 Western Pacific Housing Inc. 1210 Central Boulevard ENVIRONMENT HEALTH Brentwood,California 94513 PERMIT/SERVICES Subject: Petroleum Hydrocarbon Impacted Soil Excavation Lathrop Station McKee Lathrop,California Tetra Tech Project Number: P2261.04.1.NBS0.0001.3D Dear Mr. Compaglia: On October 7, 2003, Tetra Tech EMI Inc. (Tetra Tech) prepared a Phase I Environmental Site Assessment (ESA) of the Lathrop Station McKee property located at 410 Louise Avenue, Lathrop, California (Tetra Tech Project P2261.04.1.NBSO.0001.lA). The results of the Phase I ESA, indicated the presence of stained soil located around the on-site shed and beneath three elevated aboveground storage tanks (AST) located near the shed. Tetra Tech recommended collecting soil samples from the affected areas and analyzing the soil for total petroleum hydrocarbons to determine any adverse impacts. On October 29,2003,Tetra Tech conducted limited soils sampling in the areas of staining. Sample analysis of the area of the ASTs indicates the presence of total petroleum hydrocarbons as motor oil (TPH-mo) above the California Regional Water Quality Control Board (RWQCB) Risk Based Screening Level(RBSL)to a depth of at least 1 foot,but to no greater than a depth of 4 feet below ground surface(bgs). The highest concentrations of TPH-mo were detected in the 1-foot bgs soil samples collected from borings B1 and B2 at 1,400 and 4,200 mg/kg,respectively. TPH-mo was not detected in any of the samples collected at 4 feet bgs,with the exception of B2. The concentration at 4 feet bgs in B2 did not exceed the RWQCB RBSLs for residential use. Based on the soil sample analysis and the results of photoionization detector readings, no additional, deeper samples were deemed necessary. Tetra Tech recommended that the impacted soil in the area of the ASTs be excavated and disposed of properly. On April 16, 2004, Ms. Cathy Reed of Tetra Tech directed the excavation and observed the removal of approximately 18 cubic yards of contaminated soil (approximately 10 feet by 10 feet by 5 feet deep) beneath the former area of the ASTs. The three ASTs had been relocated to an area approximately 50 feet east of their former location. The ASTs appeared to be empty and no staining was observed on the soil beneath the ASTs. The excavated soil was loaded into a transport truck, and disposed at the Vasco Road Landfill as non-hazardous Class H waste. The excavation was backfilled with import material. Ca contains recycled fiber and is recyclable