COMPLIANCE INFO_PRE 2019 - Laserfiche WebLink

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Marketing recently developed a proactive and vigorous program aimed at making leaks in aboveground storage tanks (ASTs) a thing of the past. It is modeled upon the highly successful underground storage tank program. Chevron's highly effective Underground Tank Program leads us to our new Aboveground Tank Program. Tank Integrity Programs (TIPs) This long-term program is proactive and environmentally oriented. It attempts to ensure that the fuel container or tank has no leaks or spills as a result of corrosion attack, brittle fracture, ductile tearing, overstressing, extreme shaking (seismic activities), etc., and it includes three elements. 1. Inspection A comprehensive series of inspections and evaluations is required. Although in the past tanks were operated indefinitely without an overhaul, our current inspection program requires that the tank be shut down, cleaned, and internally inspected at periodic intervals. Even though there are many different types of inspections, the two most important are the internal and external inspections. The internal inspection occurs at intervals not exceeding 20 years. Chevron requires a 10 -year inspection cycle if the tanks do not meet our stringent standards for double bottoms, if corrosion rates are high, or when states specifically control the internal inspection frequency. We conduct external inspections every 5 years. Chevron relies on the the best available industry standards such as API 653 for this purpose. These inspections not only review the quality of the materials, but document problems, trigger future inspections, and maintain a systematic approach. Our goal is to increase the possibility that all aspects of all tanks are checked at appropriate times and that each tank is fit for service. These inspections are performed by API Certified inspectors who have met stringent qualification and follow requirements set by the American Petroleum Institute (API). Aboveground Tank Program. 2. Double Bottom Program The bottom of existing tanks can fail due to corrosion, resulting in leaks that may go undetected for extended intervals. Chevron has implemented the double bottom program to address this possibility. We use five layers of protection to reduce the probability that slow leaks enter the ground or tank foundation. The cutaway graphic explains these layers. The old tank bottom could be considered a liner or barrier to leakage; however, we do not rely on this. When a tank is inspected, we place an impermeable HDPE (high density polyethylene) liner—a liquid -tight pan—over the bottom. The new steel bottom acts as a primary barrier, and its life is extended by a coating layer that prevents any water from corroding the steel. For new tanks we use a liner under the tank prior to construction which performs the same function as the double bottom tank. We believe that Chevron is the only company with a formal and comprehensive double bottom program. 3. Overfill Prevention Even if the mechanical integrity of the tank could be guaranteed, overfills can still happen. Chevron has studied the causes of overfills and has concluded that all of the critical elements of a program that can substantially reduce overfills are included in the new API Standard 2350. Although the standard is too new to have many regulations requiring its use, Chevron has adopted the principles in the standard as a policy and gone beyond the requirements of this standard as well. The cutaway graph on the right side of the inner fold out provides a brief description of how the overfill protection system operates. There are 3 key elements that support the TIP for AST's Integrity Processes Tank Integrity Program • Double Bottoms • API Inspections • Overfill Prevention Quality Processes Product Integrity Process • Water and Particulates Control • Floating Suctions • Covered Tanks • Coated Bottoms • Sloped Bottoms Safety Processes Incident Prevention Programs • Incident Free Operations • Loss Prevention System