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Draft Limited Phase II Site Investigation Austin Road-SR 99 Van Till Property Acquisition BCI File No. 2643.x Manteca California October 23 2013 INTRODUCTION Blackburn Consulting(BCI)prepared this Limited Phase II Site Investigation(PSI)for the Austin Road—SR99 Van Till Property Acquisition(APN 228-050-03)project located in Manteca, CA. This PSI is based on the direction provided by Caltrans via email of September 19,2013 and subsequently revised on September 23,2013. The PSI is designed to address potential hazardous material issues that can affect project planning, design, and/or Caltrans right- of-way (ROW) acquisition requirements. Figure 1 presents the Vicinity Map. Project Description The Austin Road-SR 99 Van Till acquisition parcel (APN 228-050-03)was historically developed as a dairy farm. The parcel in its entirety was acquired by Austin Road Business Partners LLC for community development. Subsequently, Caltrans is to acquire a 0.51 acre portion of the parcel in order to extend the existing Caltrans ROW along the on-ramp to northbound SR99. A Phase I Environmental Site Assessment Report was prepared by HDR Environmental in May 2013 for the Austin Road Interchange in accordance with ASTME 1527- 05 Standard Practice for Environmental Site Assessments: Phase I Environmental Site Assessment Process. HDR recommended no further action at the site. However, Caltrans requires a confirmatory hazardous materials site investigation to determine whether potential contamination is present on the property prior to property acquisition. Assessment Objectives The Phase I Report(HDR 2013) did not identify any specific hazardous material issues in the acquisition area; however, Caltrans requested three potential general contamination issues to be assessed. These general contamination issues consist of. 1) Pesticides/heavy metals The purpose of the assessment is to evaluate the parcel for residues of persistent pesticides and associated heavy metals in the upper approximate two feet of soil. The screening focused on common historically-used pesticides which have been found to be persistent in the environment. These pesticides include lead arsenate and organochlorine compounds such as DDT and its breakdown products. 2) Aerially Deposited Lead(ADL) Aerially Deposited Lead(ADL)has been found to occur in soils adjacent to highways. The lead is presumably from the historical use of leaded gasoline and subsequent exhaust emissions. At sites where the shoulder subgrade has not been disturbed,the presence of ADL is generally limited to the upper twenty-four(24) inches of the unpaved shoulder and median areas. The assessment focused on the upper two feet of soil. 3) Total Petroleum Hydrocarbons (TPH) The purpose of the assessment is to evaluate the portion of the parcel to be acquired for Total Petroleum Hydrocarbons(TPH)that may be present in the groundwater and/or soil at 25-feet 1