V & A Consulting Engineers CSA 20240214

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Consulting Services Agreement between City of San Leandro and Last revised 2/14/2024 V&A CONSULTING ENGINEERS for CONCRETE STRUCTURES CONDITION ASSESSMENT Exhibit A – Page 2 of 3 delamination within the concrete substrate. Delaminated areas will be marked with chalk for reporting purposes. iii. Conduct penetration measurements (using a chipping hammer) to find the depth to sound material at one location per structure, as needed. iv. Measure the surface pH of the concrete surfaces at the concrete penetration test locations described above. The pH of concrete can substantiate the extent of degradation. v. For Digester 4, V&A will enter the structure from the side manway(s) and assess the concrete wall and steel roof from the floor of the digester. V&A will also assess the steel roof and upper concrete wall from available access openings in the roof using a tripod mounted 360 -degree camera equipped with a lighting apparatus. V&A will retain a scaffolding contractor to install a rolling 10’x10’ tower scaffold with a standing height of approximately 25’ to reach accessible areas of the steel roof. V&A will provide confined space entry support for the scaffolding contractor to install and remove the scaffolding. The scaffolding can be left in place for up to one month without additional charges. V&A will conduct A-scan ultrasonic thickness (UT) testing of the steel roof of the digester to determine baseline thicknesses and the extent of corrosion that may be present. Up to 32 measurements will be taken on accessible portions of the roof shell and roof skirt. The field engineer will obtain up to five pit depth readings at locations exhibiting excessive corrosion on the surface that prevents reliable UT measurement. vi. Concrete coring: V&A will retain a coring contractor for one (1) day (only) to drill up to six (6) 3 - inch diameter by 6-inch-deep cores, repair core holes, and conduct laboratory analysis. Notecores are typically collected in pairs with one of the cores used for compressive strength testing and the other core for the remaining tests. Laboratory analysis of cores will be as indicated below. vii. Compressive strength testing on 3 cores. viii. Incremental chloride testing on 3 cores (four half-inch increments). ix. Incremental pH at various depths on 3 cores (four half-inch increments). x. Phenolphthalein indicator testing (carbonation on cross-section) on 3 cores. 5. Report: Prepare a condition assessment report that describes the field assessment methods, activities, results, and conclusions. The report will include photographs of the existing conditions, data tables, and graphical and illustrative figures, as required, to present the information gathered during this assessment. The locations and severity of defects will be noted, and the current condition of the structure regarding its state of degradation will be described based on the results of the assessment. Recommendations for rehabilitation, repair, further assessment, or reassessment will be presented in the report, as needed, along with probable cost estimates. A draft electronic copy of the report will be submitted for review. Comments will be incorporated, and a final electronic copy will be provided. Any changes to the following assumptions, prevailing wage assumption, exclusions and limitations, or proposed schedule may necessitate an adjustment to the proposed fee. DocuSign Envelope ID: B1FEB12C-3187-4688-9A64-AA6A32699F6E