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