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Home My WebLink About2023 CATHODIC May 4, 2023 Jaco Oil Company P.O. Box 82515 Bakersfield, CA 93380 2515 Attention: Mr. Chris David Subject: Operational Testing of the Cathodic Protection System at Howards Mini Mart, 3300 Planz Road in Bakersfield, California. Dear Mr. David: On May 2, 2023, Farwest Corrosion Control Company conducted a cathodic protection system inspection on the Howards Mini Mart underground fuel storage tanks. Upon completion of the inspection, repairs and system adjustments, all pipe-to-soil potentials on underground structures met or exceeded NACE criteria for cathodic protection. All cathodic protection components appeared to be in good repair and functioning normally except as noted below. BACKGROUND: At the request of Jaco Oil Company, Farwest Corrosion Control performed an inspection and survey on the impressed current cathodic protection (CP) system designed to protect three (3) underground storage tanks (UST’s) at Howards Mini Mart 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 100 Volt, 20 Amp rectifier is located in the outside storage area on the north side of the building, with an unknown number of anodes installed in the front parking lot of the building. 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 4, 2023 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: 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 next to the Vent Pipes on the southwest corner of the back of the building to get the structure-to-soil potential measurements off the vent pipes , fuel dispensers and the storage tanks. Rectifier current and voltage outputs were measured with the same Fluke multimeter. Rectifier output was interrupted with a Tinker & Rasor TI-50 50 amp current interrupter set at intervals of 9.5 seconds “ON” and 0.5 seconds “OFF” in order to obtain “Instant OFF” potentials on the three protected UST’s. Reliance on the “Instant OFF” survey method confirms compliance with NACE Criteria 5.2.1.2 by measuring polarized potentials independent of voltage influenced by circuit resistance. The “Instant OFF” data also contributes one factor to NACE Criteria 5.2.1.3. The other factor to NACE Criteria 5.2.1.3 is a depolarized potential measurement that was achieved by shutting the rectifier off for 24 hours allowing for the depolarizing of the cathodic protection system. NACE Criteria 5.2.1.3 states that a minimum of 100 millivolts of polarization is required to fully satisfy this criteria. The 100 millivolts of polarization was established by taking the “Instant OFF” potential and subtracting the depolarized potential. As long as at least 100 millivolts was achieved on all test locations the UST’s are considered to be cathodically protected. MAY 2023 RESULTS: Upon arrival, the rectifier was found on and functioning as intended and all other system components were found to be fully functional and operating as designed. All test locations satisfied NACE Criteria 5.2.1.3 with achieving greater than 100 millivolts of polarization ranging from 118 to 129 millivolts. (See attached data sheet). All gas station rectifiers are required to have an hour meter on their rectifiers to document the time that the rectifiers are functional. Howards Mini Mart’s rectifier was not built with an hour meter. May 4, 2023 3 RECOMMENDATIONS: 1. Install an hour meter into the rectifier to document the rectifier’s functioning time. 2. 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. 3. 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. 4. 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 4, 2023 Job Number: B6328 Job Number B6328 Weather 55° Sunny Date 5/2/2023 Meter Fluke 87 V Multimeter Inspector Dennis Clothier Calibration 1/12/2023 Company Jaco Oil - Howard's Mini Mart Reference CUCUSO₄ Protected Structure Underground Storage Tanks Calibration 5/2/2023 Rectifier Location Outside in Storage Area Comments ±2.6mV Field to Calibration Reference Electrode Please Note if Rectifier is 480 VAC Make/Mfr.Mesa BEFORE AFTER -ADJUSMENT Model No.AVAI Indicated DCV 71.00 Serial No.060220 Indicated DCA 4.00 DC Volt Rating 100 Measure DCV 73.68 DC AMP Rating 20 Shunt Size AC Volt Rating 12.2 Shunt reading (mV)6.84 AC AMP Rating 12.2 Calculated Amps 3.42 GPS location N35.32541 W119.03944 GPS Junction Box Unknown Tap Coarse Not Applicable GPS Datum WGS 84 Tap Fine Not Applicable Structure "ON""OFF"Depolarized Polarization Shift Pumps 1 & 2 -903 -663 -534 129 Pumps 3 & 4 -893 -662 -535 127 East Vent Pipe -910 -663 -537 126 Middle Vent Pipe -896 -655 -537 118 West Vent Pipe -895 -656 -537 119 South Tank -910 -660 -534 126 Middle Tank -896 -657 -535 122 North Tank -900 -661 -534 127 Rectifier made with no Hour Meter Recommendation Next Inspection Date May 2026 Actions Rectiier location is in shed area on the North Side of the Building Rectifier current dial set at 60 out of 100 Install an Hour Meter into the rectifier Comment Interrupter set at 9.5 seconds "On" and 0.5 seconds "Off". Nace Criteria Satisfied Nace Criteria Satisfied Nace Criteria Satisfied Nace Criteria Satisfied Nace Criteria Satisfied Nace Criteria Satisfied Nace Criteria Satisfied Status of Cathodic Protection Use 1 sheet per Rectifier 50mV/25A Farwest Corrosion - Cathodic Protection Inspection Sheet General Information Rectifier Data Potential Data (Millivolts - Cu/CuSO4) Nace Criteria Satisfied 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 V 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 Howards Mini Mart Dennis Clothier / Farwest Corrosion CP-2 Corrosion Technician 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