Item 16 - Agreements for A -Tech Consulting, Inc., Dudek, and Leighton Consulting, Inc. for On -Call Various Environmental Services

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SCOPE OF WORK Phase I Environmental Site Assessments (ESA) Leighton will complete Phase I ESAs in conformance with the American Society for Testing and Materials (ASTM) International standard E 1527-21, All Appropriate Inquiries (AAI) 40 CFR Part 312, November 1, 2005, and, if required, Caltrans Project Development Procedures Manual, Chapter 18. Phase I ESAs completed by Leighton will include at a minimum: Records Review, Site Reconnaissance, Interviews, Report Preparation. All Phase I ESAs will include conclusions specific to the particular project as well as recommendations for additional investigation (Phase II ESA) as applicable. Phase I ESAs will be completed under the direction of registered professionals, including Environmental Professionals as required by AAI. Leighton will adhere to pertinent new regulatory requirements as applicable during the course of the contract, including those of E2600-10 for Tier 1 Vapor Encroachment Screening and as directed by the City. Interviews of tenants and or property owners will be completed with the City's authorization. Upon receipt of your authorization, we will make initial contact with property owners to conduct interviews of present and/or past owners, lessees, and employees (if they are available and cooperative). Our goal is to move your project forward —not introduce impediments. We will do everything possible to work within the unique sensitivities of each specific project. Phase ll ESA Leighton understands that remedial investigations/ site characterizations may be required for properties identified as having potential contamination in the performance of a Phase I ESA, properties involved in acquisitions, construction improvements or development. The primary goals of an environmental site investigation are to assess the nature and extent of any impacts, quantify the approximate mass of contamination, evaluate potential risk to human health or the environment, and provide recommendations for further investigation or remedial action, if required. Based upon our experience in California, the typical contaminants in soil and/or groundwater include petroleum hydrocarbons, volatile organic compounds (VOCs), semi -volatile organic compounds (SVOCs), polychlorinated biphenyls (PCBs), Organochlorine Pesticides (OCPs) and heavy metals, but the potential for additional contaminants does exist. Leighton will employ a variety of technical approaches to expedite site assessment activities. The selection of the most appropriate assessment approach will be based upon City goals, site access and schedule. Each project is different and Leighton will make it a top priority to work with the City to find the most technically feasible, sustainable, and cost-effective approach to each project, with site closure and/or construction completion as the final goal. Tools and investigation techniques that Leighton typically employ include the following: • The use of geo-located current and historical aerial photographs combined with hand-held GPS units allow for more accurately targeted investigations in the field. • Soil vapor surveys, which provide excellent real time data that can pinpoint potential sources warranting further soil or groundwater sampling. • The use of direct -push borings for investigation of soils and groundwater which nearly eliminates the costs associated with the characterization and disposal of investigation -derived wastes. • Determination of site specific cleanup levels by establishing background levels prior to or during the investigation using screening methods such as XRF. This can help limit additional delineation requirements and reduce the overall investigative cost. • The use of Rapid Optical Cone Penetrometer (CPT) or Rapid Optical Screening Tool (ROST) technologies to screen soils for the presence of petroleum hydrocarbons. • Employing forensic chemical studies using chromatographic finger printing, chemical ratio comparisons, degradation by-product and isotope age dating, off -site source reviews and area -wide groundwater gradient interpretation to assess sources of historical chemical releases. • The use of mobile laboratories to expedite field decisions. • The use of closed circuit television (CCTV) to investigate and map (using subsurface sounding and surface survey) subsurface utilities as potential conduits or release points allowing for forensic engineering analysis of these structures and pinpointing of release locations. Leighton 9