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C S I Proposal 3003 -As Needed Services Reservoir Inspection, Cleaning and Repairs Project No.#OSD 2021-604 SERVICES City of Pleasanton Page 4 Scope of Services CST's is specifically proposing to meet the inspection requirements in the Request for Proposal. Although we have the ability, we are not proposing to complete any tank cleanings. The defined tasks our Scope of Services follow: Field Work Tank Dive Assessments - It is understood that the goal of this task is to complete tank assessment to determine sound maintenance strategies and plans for maintaining the structures. Surveys of both the internal and external surfaces of potable or non-potable steel reservoirs will be completed. The surveys can be completed with the tanks in operation. This specific task of completing a dive inspection is described below. Our proposal assumes that tanks have satisfactory access roads and that access to a tank exterior roof can be made from ladders. Underwater surveys would be performed while a tank is full of water using special underwater techniques and AWWA C652 sanitary procedures for potable tanks. The survey will be conducted by a team of highly trained and certified inspectors having exceptional diving and underwater photography skills. During the evaluations, particular attention will be paid to the condition of the following critical areas: Roof Piping Manways Roof Structure Vents/Screens Hatches Shell Shell and Roof Chine/Joints Gaskets Tank Bottom Weld or Bolt Connections Ringwall/Anchor Bolts Overflow Pipe/Weir Ladders/Safety Climbs Grade/Tank Crevices Drains/Sumps Vandal Deterrents Water Level Indicators Inlets/Outlets Platforms/Railings CP Equipment/Components The focus of the inspections will be to evaluate the current condition of the interior and exterior coating systems and the level of corrosion on the tanks. The evaluation will involve visual observations, dry film thickness (DFT) measurements, adhesion testing, and potentially corrosion pit depth and/or ultrasonic (UT) testing for steel thickness measurements. Visual exterior observations will note the degree of exterior paint chalking and any breaks, blisters, or other coating defects. It is not the intent of this exterior evaluation work to make access to any surfaces that cannot be surveyed from the tank ladder(s) or catwalks (i.e. repelling is not included with in this scope). The degree of chalking will be determined in general accordance with ASTM D4214 "Standard Test Method for Evaluating the Degree of Chalking of Exterior Paint Films" and areas of rusting will be quantified in accordance with ASTM D610 "Standard Test Method for Evaluating the Degree of Rusting of Painted Steel Surfaces." Dry film thickness (DFT) measurements will be obtained in general accordance with SSPC: The Society of Protective Coatings Paint Application Specification No. 2 "Measurement of Dry Film Thickness with Magnetic Gages" and exterior paint adhesion will be assessed using ASTM D3359 "Standard Test Method for Evaluating Adhesion by Tape August 23, 2021