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Sampling and Analysis Plan 1 Introduction HDR, Inc. (HDR) as prepared this Phase II Environmental Site Assessment (ESA) Sampling and Analysis Plan (SAP)for the Stockton Diamond rail grade separation project (Project) located in the City of Stockton, California. A Phase I ESA was previously conducted by HDR (HDR, 2022) at sixteen discrete properties (referred to as "Subject Properties" herein) associated with the Project as shown on Figure 1.1. Recognized environmental conditions (RECs) or historical recognized environmental conditions (HRECs)were identified at eleven of sixteen Subject Properties as potentially containing hazardous substances or petroleum products in the subsurface. The Subject Properties where RECs or HRECs have been identified have been selected for investigation to determine whether contaminants may be present in the subsurface which may require management during Project construction. This SAP describes the basis and tasks that will be followed during performance of the Subject Property investigations. Tasks include soil sampling, groundwater sampling, management of investigative derived waste (IDW), data analysis, and report preparation. 1 .1 Sampling and Analysis Objective The objective of this ESA is to identify the presence of contaminants in the subsurface that could materially affect construction activities at each of the sixteen Subject Properties located along the Project alignment (Figure 1.1). The Project is anticipated to generate soil via excavation from each of the Subject Properties. The depth of soil excavation varies by property depending upon the construction activity at a particular property. Although groundwater is not expected to be generated as part of the construction activities, groundwater sample will be collected at selected properties as an exception protocol. This SAP has been prepared in general accordance with ASTM International (ASTM) E 1903-19 Standard Practice for ESAs to identify methods for the subsurface investigation to characterize contaminants that may be encountered during Project construction. 2 Sampling Rationale The procedure for determining whether a Subject Property is recommended for sampling of soil and groundwater consisted of compiling and reviewing information from the following sources: • Review the Phase I ESA (HDR, 2022) to verify whether the Subject Property or adjacent properties were identified as RECs or HRECs, • Whether soil or groundwater will be disturbed during Project construction on Subject Properties where RECs or HRECs were identified; • If information on soil or groundwater contamination may be necessary to determine Project construction worker health and safety requirements, waste disposal profiling; June 24,2022 1 4