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Home My WebLink About2023 CATHODIC (5-5-2023) May 5, 2023 Job Number B6348 Golden State Mobil 3200 F Street Bakersfield, CA 93301 1826 Attention: Mr. Monty Singh Subject: Operational Testing of the Cathodic Protection System at Golden State Mobil, 3200 F Street in Bakersfield, California. Dear Mr. Singh: On May 2, 2023, Farwest Corrosion Control Company conducted a cathodic protection system inspection on the Golden State Mobil Gas station’s underground fuel storage tanks. Upon completion of the inspection, repairs and system adjustments, all pipe-to-soil potentials on underground structures did not meet or exceeded NACE criteria for cathodic protection. BACKGROUND: At the request of Golden State Mobil, Farwest Corrosion Control performed an inspection and survey on the impressed current cathodic protection (CP) system designed to protect two (2) underground storage tanks (UST’s) at Golden State Mobil in Bakersfield, California. The purpose of the inspection was to test the effectiveness of the impressed current cathodic protection system on the three underground fuel storage tanks. The 50 Volt, 12 Amp rectifier is located in the storage room within the store. The anode ground bed is located on the south side of the store in the parking lot. Drawings and historical data were not available at the time of this survey. CATHODIC PROTECTION CRITERIA All potential levels measured and recorded are referenced to the criteria for cathodic protection as established by the National Association of Corrosion Engineers standard SP0285-2021 “External Corrosion Control of Underground Storage Tank Systems by Cathodic Protection,” Section 5.2 which provides the following: 5.2 Criteria for Steel Structures 5.2.1 Corrosion control can be achieved at various levels of cathodic polarization depending on the environmental conditions. However, in the absence of data that demonstrate that adequate CP has been achieved, one or more of the following shall apply: May 5, 2023 Job Number B6348 2 5.2.1.1 A negative (cathodic) potential of at least 850 mV with the CP applied. This potential is measured with respect to a CSE contacting the electrolyte. Voltage drops other than those across the structure/electrolyte boundary must be considered for valid interpretation of this potential measurement. 5.2.1.2 A negative polarized potential of at least 850 mV relative to a CSE. 5.2.1.3 A minimum of 100 mV of cathodic polarization. The formation or decay of polarization may be used to satisfy this criterion. TEST PROCEDURES: Depolarized structure-to-soil potentials were recorded using a calibrated Fluke 87 V digital multimeter and a calibrated portable M.C. Miller copper/copper sulfate (Cu/CuSO₄) reference electrode placed in soil on the southwest corner of the parking lot to get the structure-to-soil potential measurements off the vent pipes , fuel dispensers and the storage tanks. MAY 2023 RESULTS: Upon arrival, the rectifier was found in the “On” position. However, no volts or amps were present. Troubleshooting indicated that the fuse had gone bad. Farwest replaced the fuse and turned the rectifier back on. Voltage came back to the rectifier, but the amps did not. Further investigation revealed that some time previously the structure lead to the rectifier and the main anode lead from the anode groundbed to the rectifier had been severed and wire nuts had been placed on the wires. There were no wires within the conduit going into the ground. However, the structure lead and the main anode lead’s continuity testing indicated that the wires from the electrical box, in which the wires were found, to the rectifier were continuous. This indicates that the wires from the rectifier to the electrical box should be good. The depolarized structure-to-soil potentials measured were within expectations for steel in soil and without cathodic protection applied. (See attached data sheet). RECOMMENDATIONS: 1. Expose the severed structure and main anode leads from under the parking lot and have a cathodic protection professional splice the wires found under the parking lot to the wires within the electrical box. 2. Once the wires are spliced and the rectifier is turned back on and Volts and Amps are measured on the rectifier, a CP survey will have to be performed by a cathodic protection professional. 3. While State of California regulations require that impressed current CP systems protecting underground fuel storage tanks be inspected no less than every 60 calendar days, we recommend you read and record the voltage and current outputs of the rectifier every month. If voltage and/or current outputs change more than ±10% please call us to inspect the CP system. May 5, 2023 Job Number B6348 3 4. Although the state requires full testing of underground storage tank CP systems every three years, Farwest recommends that a qualified corrosion engineer or technician test the entire cathodic protection system annually. 5. Any electrical or mechanical modifications to these cathodically protected structures should be reviewed by a qualified corrosion professional to ensure that electrical isolation is not compromised. We trust that the enclosed information is adequate for your needs. If you have any questions, or if we can assist you in any way, please do not hesitate to call our office at (661) 323-2077. Sincerely, FARWEST CORROSION CONTROL COMPANY Dennis Clothier NACE CP Technician #40506 May 5, 2023 Job Number: B6348 Job Number B6348 Weather 55° Sunny Date 5/2/2023 Meter Fluke 87 V Multimeter Inspector Dennis Clothier Calibration 1/12/2023 Company Golden State Mobil Reference CUCUSO₄ Protected Structure Underground Storage Tanks Calibration 5/2/2023 Rectifier Location Storage Room Comments ±2.6mV Field to Calibration Reference Electrode Please Note if Rectifier is 480 VAC Make/Mfr.JA Electronics BEFORE AFTER -ADJUSMENT Model No.SS-1 Indicated DCV 0.00 Serial No.97175 Indicated DCA 0.00 DC Volt Rating 50 Measure DCV 0.00 DC AMP Rating 12 Shunt Size AC Volt Rating 115 Shunt reading (mV)0.00 AC AMP Rating Not Applicable Calculated Amps 0.00 GPS location N35.38860 W119.02303 GPS Junction Box Anodes in Road Box Tap Coarse B/D GPS Datum WGS 84 Tap Fine 2/6 Structure "ON""OFF"Depolarized Polarization Shift Vent Pipe 1 -275 Vent Pipe 2 -272 Vent Pipe 3 -269 Vent Pipe 4 -269 Pumps 1 & 2 -343 Pumps 3 & 4 -343 Pumps 5 & 6 -306 Pumps 7 & 8 -303 Pumps 9 & 10 -222 Pumps 11 & 12 -222 South East Tank -220 North East Tank -219 Recommendation Next Inspection Date May 2026 Actions Hour meter at Start of survey 16874.4 Hour meter at end of survey 16874.4 Splice structure and anode main leads back into the CP System and retest entire CP System. Comment Structure and anode main leads found severed. Rectifier left off. Rectifier found with a blown fuse. Farwest replaced fuse on 5/2/2023. Farwest Corrosion - Cathodic Protection Inspection Sheet General Information Rectifier Data Potential Data (Millivolts - Cu/CuSO4) Status of Cathodic Protection Use 1 sheet per Rectifier 50mV/15A Data Page 1 of 1 Facility Technician YES NO N/A mVDC YES NO N/A mVDC YES NO Comments: Cu/CuSO4 * +/- 5 mVDC Requires Maintenance Reference Electrode? ± 2.6mV measured between Field Reference Electrode and Office Control Reference Electrode. Require Maintenance? Meter & Model Meter or DVM Card Serial # Fluke Digital Mutimeter Model 87 90960497 Meter Last Calibration Date Was Reference Electrode Reference Electrode prior to Inspection calibrated prior to inspection? Did Reference Electrode Reference Electrode after Inspection 5/2/2023 5/2/2023 Reference Electrode Calibration Golden State Mobil Dennis Clothier / Farwest Corrosion CP-2 Corrosion Technic Inspection Start Date Inspection Completion Date OQ Report Last NameFirstNameCompany NameNumberCourse NameTypeResultCompletedDateExpirationDateProctor /EvaluatorAssigned ByUserGroupClientClothierDennisFarwestCorrosionControl Co.CT01ConductingAnnual CathodicProtectionSurveysKnowledgePass07/07/202016:29:1507/07/2023Schifferle,MichaelClothierDennisFarwestCorrosionControl Co.CT01ConductingAnnual CathodicProtectionSurveysSkillsPass07/24/202005:00:0007/24/2023Schifferle,MichaelClothierDennisFarwestCorrosionControl Co.CT02Maintain TestLeadsSkillsPass07/24/202005:00:0007/24/2023Schifferle,MichaelClothierDennisFarwestCorrosionControl Co.CT02Maintain TestLeadsKnowledgePass07/07/202017:31:0607/07/2023Schifferle,MichaelClothierDennisFarwestCorrosionControl Co.CT03InspectCathodicProtectionRectifiersSkillsPass07/28/202005:00:0007/28/2023Schifferle,MichaelClothierDennisFarwestCorrosionControl Co.CT03InspectCathodicProtectionRectifiersKnowledgePass07/14/202021:48:0107/14/2023Schifferle,MichaelClothierDennisFarwestCorrosionControl Co.CT04CathodicProtectionRectifierMaintenance andRepairSkillsPass07/28/202005:00:0007/28/2023Schifferle,MichaelClothierDennisFarwestCorrosionControl Co.CT04CathodicProtectionRectifierMaintenance andRepairKnowledgePass07/07/202019:38:2807/07/2023Schifferle,MichaelClothierDennisFarwestCorrosionControl Co.CT08ConductingCathodicProtectionRemediationKnowledgePass07/07/202021:12:5907/07/2023Schifferle,MichaelClothierDennisFarwestCorrosionControl Co.CT08ConductingCathodicProtectionRemediationSkillsPass07/24/202005:00:0007/24/2023Schifferle,MichaelClothierDennisFarwestCorrosionControl Co.CT60GeneralAbnormalOperatingConditionsKnowledgePass07/10/202022:41:1107/10/2023Schifferle,MichaelClothierDennisFarwestCorrosionControl Co.CT0031Inspect andMonitorGalvanic GroundBeds/AnodesKnowledgePass07/10/202021:35:5007/10/2023Schifferle,MichaelClothierDennisFarwestCorrosionControl Co.CT1291LocateUndergroundPipelinesKnowledgePass07/10/202018:21:4707/10/2023Schifferle,MichaelClothierDennisFarwestCorrosionControl Co.CT1291LocateUndergroundPipelinesSkillsPass07/24/202005:00:0007/24/2023Schifferle,Michael