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HomeMy WebLinkAboutMINUTES - 05021995 - 1.44 } TO: BOARD OF SUPERVISORS C�6/ ont Costa FROM: HARVEY E. BRAGDON County DIRECTOR OF COMMUNITY DEVELOPMENT � �`� DATE: May 2, 1995 SUBJECT: Ratification of the Zoning Administrator' s Decision Regarding Shell Oil Company' s Compliance with Conditions of Approval (LUP 2009-92) SPECIFIC REQUEST (S) OR RECOMMENDATIONS) & BACKGROUND AND JUSTIFICATION RECOMMENDATIONS Ratify the Zoning Administrator' s decision that Shell Oil Company has complied with Condition of Approval #22 for the C5 Tank. FISCAL IMPACT None. BACKGROUND/REASONS FOR RECOMMENDATIONS When the Board of Supervisors approved the Land Use Permit for Shell Oil Company' s Clean Fuels Project (County LUP #2009-92) , the Board specified that the Zoning Administrator' s decision regarding several conditions of approval be placed on the consent calendar for ratification. As directed by the Board at the October 4, 1994 meeting, the Zoning Administrator' s decisions discussed herein have been placed on the Zoning Administrator' s agenda for May 1, 1995. Any comments received at the meeting will be forwarded to the Board. 7 CONTINUED ON ATTACHMENT: %% YES SIGNAT RECOMMENDATION OF COUNTY ADMINISTRATOR RECOMMENDATION OF BO COMMITTEE APPROVE OTHER SIGNATURE (S) : ACTION OF BOARD ON May 2 , 1995 APPROVED AS RECOMMENDED x OTHER VOTE OF SUPERVISORS I HEREBY CERTIFY THAT THIS IS A x UNANIMOUS (ABSENT TRUE AND CORRECT COPY OF AN AYES : NOES : ACTION TAKEN AND ENTERED ON THE ABSENT: ABSTAIN: MINUTES OF THE BOARD OF SUPERVISORS ON THE DATE SHOWN. Contact Person: Catherine Kutsuris - 646-2036 Orig: Community Development Department ATTESTED May 2 , 1995 cc: Health Services Department: RMPP PHIL BATCHELOR, CLERK OF _Shell Oil (via CDD) THE BOARD OF SUPERVISORS AND UNTY MINISTRATOR BY - DEPUTY Ratification of decision on Shell Oil Company April 25, 1995 Page Two Condition of Approval #22 : Hazard and Operability Study This condition requires Shell Oil to prepare a Hazard and Operability Study and accident consequence analysis for all elements of the Clean Fuels Project with the exception of the office building, the control rooms and the maintenance/warehouse buildings . Shell Oil Company completed the required study for the C5 Tank. This information was evaluated by the Risk Management and Prevention Program Team of the Health Services Department. Their review included a detailed examination of the hazard analyses and off-site consequences as well as scrutiny of all the programs or aspects of the Company (e.g. , operating procedures, preventive maintenance programs and operator training) which are designed to prevent or mitigate accidents or process anomalies . The review included document assessments, management and operations personnel interviews and process "walk through" to verify documentation. The Health Services Department made several recommendations to reduce the probability or severity of accidents (refer to the attached HSD memorandum) . These recommendations were accepted by the Zoning Administrator and will be required of Shell, Oil . The Health Services Department will conduct follow-up field inspections to ensure that all recommendations have been followed. CK/db a:BOS . shl 4/17/95 Contra Costa County • Health Services Department ENVIRONMENTAL HEALTH DIVISION '4 COUI1'� OCCUPATIONAL HEALTH/HAZARDOUS MATERIALS TO: Catherine Kutsuris, County Zoning Administrator, DATE: April 17, 1995 FROM: Lewis G. Pascalli, ' Deputy Director Health Services Departm Hazardous Materials Division SUBJECT: CONSENT ITEM FOR SHELL REFINERY CLEAN FUELS PROJECT, CONDITION #22 , C5 STORAGE TANKS Executive Summary: The Contra Costa County Health Services Department (CCCHSD) Hazardous Materials Risk Management and Prevention Program Team has completed the Clean Fuels review for the Shell Martinez Manufacturing Complex' s C5 Storage Tanks, scheduled startup date of May 9 . Shell submitted a summary of the C5 Storage Tanks HazOp to your office on March 16, 1995 with a copy to CCCHSD. Process Description: The C5 Storage Tanks are located in the northeastern portion of the Shell Martinez Manufacturing Complex. The purpose of the C5 Storage Tanks is to store pentane and other C5s, which will be used in the final gasoline blending. The C5 Storage Tanks consist of three eighty foot diameter spheres and pumps to transfer the C5s to gasoline blending or to tankcar loading. The C5s will take the place of higher volatile compounds, such as butane, in the new gasoline blend. CCCHSD Findings: My staff has performed a detailed line-by-line review of the Hazard and Operability (HazOp) study performed for the C5 Storage Tanks . Design of safety systems as well as operational and maintenance issues have been addressed. Additionally, my staff has inspected the unit to verify that the construction so far conforms to the design specified. As a result of the review performed by the Risk Management and Prevention Program Engineers, the following changes are required to reduce the probability or severity of accidents to less than significant : Shell C5 Tanks, Page #1 1 . The C5 Storage Tanks are designed for a pressure of 20 pounds force per square inch gauge (psig) . These spheres are designed to relieve to the flare header under normal operating conditions at 18 psig. Under upset circumstances the spheres could release C5s to the atmosphere, since the final protection for the spheres relieve to the atmosphere at a pressure of 20 and 21 prig. The flare header is designed to operate at 3 to 4 psig at normal conditions, but when there is a major upset the flare header pressure could run as high as 21 psig. During these upset conditions the C5 storage tanks would be unable to relieve to the flare header and could potentially relieve to the atmosphere . Shell has added check valves to mitigate the possibility of the flare header gases backflowing to the C5 storage tanks . Shell also has fire water deluge valves on the spheres to keep the spheres cool in case of a fire and is able to flood the spheres with water to help prevent a release of C5s . CCCHSD believes that ideally the spheres should have been designed at a high enough pressure to always be able to relieve to the flare header. Alternately the flare header should have been designed to accommodate potential pressure surges from the C5 storage tanks . Either of these design considerations would have ensured that the spheres could always relieve to this header. Shell has designed the spheres with redundant pressure indication and controls to keep the pressure below 15 prig. Shell, also, has designed ways to cool the sphere if there is a fire to prevent the pressure from rising high enough where there could be a release to the atmosphere. CCCHSD is recommending the following items to decrease the risk of over pressuring the C5 tanks and a release to the atmosphere : l .a. The check valves to prevent backflow from the flare header should be inspected at a minimum during every turnaround. l .b. Shell is to provide to CCCHSD, by June 30, 1995, the protections in place for preventing butane and other Cos from other process units from entering the C5 storage tanks . 1 . c . Shell is to test the pressure instrumentation on the storage tanks (PI-2506, PI-2521 and PI-2533) frequently enough to ensure a minimum of 95o availability of these pressure instruments and associated alarms . l .d. Natural gas is the backup blanket gas for the storage tanks . If there is a loss of instrument air to the control valves for the natural gas to the storage tanks, both control Shell C5 Tanks, Page #2 valves will fail open. The pressure of the natural gas header is higher then the relief pressure of the pressure safety valves, that go to the atmosphere on the storage tanks . If both of the control valves would fail open, the relief valves could relieve and there would be a gas release to the atmosphere . Shell is to investigate and report the findings to CCCHSD for modifying the failsafe position of one of the natural gas control valves to fail close, upon loss of instrument air. Implementing the above items, along with the safeguards that Shell has designed into the C5 storage tanks will reduce the risk of an offsite exposure. With these changes CCCHSD will be able to accept the project for the storage tanks . 2 . CCCHSD recommends that the next Modified Hazard Review for the C5 storage tanks be documented as thoroughly as a HazOp. Shell C5 Tanks, Page #3