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C S Proposal 3003 -As Needed Services Reservoir Inspection,Cleaning and Repairs Project No.#OSD 2021-604 SERVICES City of Pleasanton Page 7 Tank Maintenance Plan (ADDED VALUE — NO CHARGE) As noted, we are also proposing to provide a Tank Maintenance Plan (TMP) as an added- value to the requested services. CSI will develop a TMP with respect to coatings work and potential CP repairs. The plan will compile the findings of all tank reports to develop a prioritized plan for all tanks viewed as a whole. This plan would include budget estimates for any recommendations. CSI routinely finds that considerable savings in maintenance (and corrosion related) costs can be realized over time by targeting maintenance repairs at the most opportunistic time to extend the life of existing paint, linings, and CP systems. This is where the value of CSI coating expertise has proven time and time again to be critical to water tank owners maintaining their structures in the most cost-effective manner. The goal of the program is to provide the long-range savings in coating work costs, while maintaining necessary corrosion protection. In some cases, the exterior aesthetic appearance of certain tanks can be more heavily weighted to meet other City needs, otherwise corrosion control throughout is the foundation for planning. Considerable savings in coating costs can be realized over time by targeting maintenance repairs at the most opportunistic time to extend the life of existing coatings. Based on the collective findings of all tanks, each tank is prioritized for future maintenance work with corresponding budgeted maintenance work estimates. Priority levels are typically defined as: Priority 1 —work required as soon as possible Priority 2—work required in 1-3 years Priority 3—work required in 3-5 years Priority 4—work required in 5-7 years Priority 5—no work required for 7-10+years Since coatings are typically the only elements on tank that substantially change, the lining and paint systems will be the primary focus of the evaluation review. Of course, if coatings are no longer performing well, significant corrosion may have developed, and this condition is most heavily weighted for priority. When developing recommendations, there are generally four possible approaches to maintenance coating. A coating can be either spot repaired, spot repaired and overcoated, or completely removed and replaced (recoated). The fourth approach is to defer any work because the coatings are either in excellent condition or are in a marginal condition with no significant corrosion. It would be best to let the coating continue to degrade. Where economically feasible, spot repairs will extend the life of a coating by preventing small film defects from becoming larger ones (undercutting). Generally speaking, once defects in a tank approach a certain percent of the total surface area, the window of opportunity for any level of spot repair closes. Whereas the breaking point between the overcoat and recoating strategies arrives when the existing coating becomes weak, brittle. checked, and/or cracked to the point that it will not tolerate an additional coat. Once this point is reached and any simple maintenance overcoat window is closed, it would be economically prudent for the coating to live out its useful life, before proceeding with a complete recoat. This is an example for where significant cost-savings can be achieved through an August 23, 2021