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Pleasanton PFAS Treatment & Wells Rehabilitation Project City of Pleasanton JDH Corrosion Consultants, Inc. 2 Inc. (Certification No. 2153). The preparation of the soil samples for chemical analysis will be in accordance with the applicable specifications. Soil Chemical Analysis Test Methods Chemical Analysis ASTM Method Chlorides D4327 pH D4972 Resistivity (as received and @ 100% saturation) G57 Sulfate D4327 Redox Potential D1498 Evaluate the results of the chemical analysis and determine the corrosivity of the soils along the pipeline alignments to the proposed materials of construction (i.e. mortar-coated steel, dielectric-coated steel and concrete cylinder pipe, etc.). 4. Conduct in-situ soil resistivities at an approximate 2,000 ft. interval along the pipeline alignment and at facility locations using the Wenner 4-pin technique. In-situ resistivities will be measured at 2.5’, 5’, 7.5’, 10’, 15’ and 20’ depths using a Soil Resistivity Meter. Barnes layer calculations will be performed to determine the corrosivity of the different soil layers to the proposed pipeline materials. Review the plans and profiles for the new water pipelines prepared by Carollo for construction details and proposed pipeline materials and determine the suitability of the proposed materials based on the collected field and laboratory data. 5. Contact adjacent utility owners, as needed, for coordination and requirements. If needed, we will contact other foreign utility owners, such as PG&E, that present potential stray current problems and discuss design measures to mitigate interference between the new water pipelines and these existing utilities. It is important to provide measures to ensure that the new water pipeline is protected against stray-current interference from any foreign pipelines. 6. Prepare Corrosion Engineering Technical Memorandum which will provide a summary of the field data collected along with the chemical analysis of the soil samples and an analysis of this data. The potential for corrosion on the various material options for the new water pipelines will be determined based on the analysis and recommendations for the long-term prevention of corrosion will be included for all pipe material options. All fieldwork and recommendations will be in compliance with applicable NACE and Local Water District Design Standards. 7. Prepare Corrosion Engineering Technical Memorandum outlining corrosion control design approach for each pipe option including appropriate stray current corrosion control requirements, if any. 8. The Manpower Estimate spreadsheet for each pipeline option will be prepared to compare costs for corrosion control for each pipe type option. 9. Provide a workshop to summarize recommendations for City of Pleasanton staff. 10. Alisal Wells and Pipeline Alternative: Conduct in-situ soil resistivities at an approximate 2,000 ft. interval along the pipeline alignment and at the well locations using the Wenner 4-pin technique. In-situ resistivities will be measured at 2.5’, 5’, 7.5’, 10’, 15’ and 20’ depths using a Soil Resistivity Meter. Barnes layer calculations will be performed to determine the corrosivity of the different soil layers to the proposed pipeline materials. Collect near surface soil sample for chemical analysis (see Item 3., above). Review